🔥 Ace MDCAT & ECAT MCQs Quiz: Master the Group Trends of Representative Elements in Chemistry! 🔬💡 | Essential Insights on Periodicity & Properties
1️⃣ Melting and boiling points of which of the following group of representative elements decrease regularly down the group:
🟦 A) Group IA
🟩 B) Group IIIA
🟪 C) Group VIIA
🟨 D) Group VIIIA
2️⃣ Which of the following s-block element forms superoxide when burned in air?
🟦 A) Li
🟩 B) Na
🟪 C) K
🟨 D) Mg
3️⃣ Which of the following formula of nitrides for alkaline earth metal is possible?
🟦 A) MN₃
🟩 B) M₂N₃
🟪 C) M₃N
🟨 D) M₃N₂
4️⃣ The flame colour of which of the following alkali metal is yellow?
🟦 A) Na
🟩 B) K
🟪 C) Rb
🟨 D) Cs
5️⃣ The chemical used in fireworks is:
🟦 A) Bleaching powder
🟩 B) Sodium bicarbonate
🟪 C) Potassium nitrate
🟨 D) Potash alum
6️⃣ Cathode in Castner-Kellner cell is:
🟦 A) Titanium blocks
🟩 B) Carbon rods
🟪 C) Mercury
🟨 D) Iron container
7️⃣ The diagonal member of beryllium is:
🟦 A) Mg
🟩 B) Al
🟪 C) Si
🟨 D) C
8️⃣ Purification of Sulphur dioxide from arsenic oxide is an essential step in the contact process to avoid:
🟦 A) Catalyst poisoning
🟩 B) Temperature elevation
🟪 C) Pressure controlling
🟨 D) Air mixing
9️⃣ Oil of vitriol refers to:
🟦 A) Borax
🟩 B) Sulphuric Acid
🟪 C) Alum
🟨 D) Caustic soda
🔟 The best oxidizing agent among halogens is:
🟦 A) F₂
🟩 B) Cl₂
🟪 C) Br₂
🟨 D) I₂
1️⃣1️⃣ The electronic configuration of s-block metal, M is 1s² 2s² 2p⁶ 3s¹. The formula of its oxide would be:
🟦 A) MO
🟩 B) M₂O
🟪 C) M₂O₂
🟨 D) MO₂
1️⃣2️⃣ The element lithium bears resemblance with:
🟦 A) Al
🟩 B) Mg
🟪 C) Si
🟨 D) None of them
1️⃣3️⃣ The electronic configuration of a metal, M is 1s² 2s². The diagonal member of this element has electronic configuration:
🟦 A) 1s² 2s¹
🟩 B) 1s² 2s² 2p⁶ 3s¹
🟪 C) 1s² 2s² 2p⁶ 3s² 3p¹
🟨 D) 1s²
1️⃣4️⃣ Which of the following s-block element only forms normal oxide when burned in air?
🟦 A) Li
🟩 B) Be
🟪 C) Mg
🟨 D) All of them
1️⃣5️⃣ Which of the following alkali metal only forms normal oxide when burned in air?
🟦 A) Li
🟩 B) Be
🟪 C) Ca
🟨 D) Na
1️⃣6️⃣ Which of the following formula of nitrides for alkali metal is possible?
🟦 A) MN₃
🟩 B) M₂N₃
🟪 C) M₃N
🟨 D) MN
1️⃣7️⃣ Which of the following formula of nitrides for group IIIA is possible?
🟦 A) MN₃
🟩 B) M₂N₃
🟪 C) M₃N
🟨 D) MN
1️⃣8️⃣ Which group elements form nitrides with general formula M₃N₄?
🟦 A) IIIA
🟩 B) IIA
🟪 C) VA
🟨 D) IVA
1️⃣9️⃣ Which group elements form nitrides with general formula M₃N₅?
🟦 A) IIIA
🟩 B) IVA
🟪 C) VA
🟨 D) IIA
2️⃣0️⃣ Which group elements form superoxides with general formula MO₂?
🟦 A) IA
🟩 B) IVA
🟪 C) IIIA
🟨 D) IIA
2️⃣1️⃣ Which of the following gas is evolved when phosphorus reacts with water?
🟦 A) NH₃
🟩 B) PH₃
🟪 C) H₂
🟨 D) H₂S
2️⃣2️⃣ The general formula of alkali metal alkoxide is:
🟦 A) C₂H₅OM
🟩 B) C₂H₅COONa
🟪 C) (C₂H₅)₂M
🟨 D) None of them
2️⃣3️⃣ The chemical formula of lithium Ethoxide is:
🟦 A) (C₂H₅)₂Li
🟩 B) C₂H₅COOLi
🟪 C) C₂H₅OLi
🟨 D) None of them
2️⃣4️⃣ Alkali metals react with alcohols liberating hydrogen gas along with:
🟦 A) Alkoxide
🟩 B) Phenoxide
🟪 C) Carboxylate
🟨 D) None of them
2️⃣5️⃣ The group IA elements react violently with water making the solution:
🟦 A) Acidic
🟩 B) Neutral
🟪 C) Alkaline
🟨 D) Amphoteric
2️⃣6️⃣ Which of the following alkali metals imparts lilac colour to the flame?
🟦 A) K
🟩 B) Li
🟪 C) Cs
🟨 D) Na
2️⃣7️⃣ Which of the following metals floats over water?
🟦 A) Cs
🟩 B) Na
🟪 C) Rb
🟨 D) Be
2️⃣8️⃣ The basic strength of alkaline earth metals oxides in water _____ from Be to Ba.
🟦 A) Decreases
🟩 B) Increases
🟪 C) Remains same
🟨 D) Not predictable
2️⃣9️⃣ The element cesium bears resemblance with:
🟦 A) Cr
🟩 B) Ca
🟪 C) Both A and B
🟨 D) None of them
3️⃣0️⃣ Which of the following sulphates is NOT soluble in water?
🟦 A) BaSO₄
🟩 B) ZnSO₄
🟪 C) K₂SO₄
🟨 D) Na₂SO₄
3️⃣1️⃣ The chemical formula of Chile saltpeter is:
🟦 A) KNO₃
🟩 B) NaNO₃
🟪 C) AgNO₃
🟨 D) None of them
3️⃣2️⃣ Which compound is lunar caustic?
🟦 A) KNO₃
🟩 B) NaNO₃
🟪 C) AgNO₃
🟨 D) None of them
3️⃣3️⃣ Which one of the following metals is a self-protected metal?
🟦 A) Magnesium
🟩 B) Beryllium
🟪 C) Aluminium
🟨 D) All of them
3️⃣4️⃣ Which alkaline earth metal does not react with either cold water or steam?
🟦 A) Magnesium
🟩 B) Beryllium
🟪 C) Aluminium
🟨 D) All of them
3️⃣5️⃣ Which alkaline earth metal reacts with boiling water and steam?
🟦 A) Magnesium
🟩 B) Beryllium
🟪 C) Aluminium
🟨 D) All of them
3️⃣6️⃣ Most alkali and alkaline earths react violently with water liberating H₂ gas along with respective alkalis or metal hydroxides with general formula …………….. respectively.
🟦 A) MOH, M’(OH)₃
🟩 B) M’(OH)₂, MOH
🟪 C) M’(OH)₃, MOH
🟨 D) MOH, M’(OH)₂
3️⃣7️⃣ The chemical formula of peroxides and normal oxide of strontium is respectively:
🟦 A) SrO₂, Sr₂O
🟩 B) SrO₂, SrO
🟪 C) SrO, SrO₂
🟨 D) Sr₂O₂, SrO₂
3️⃣8️⃣ The chemical formula of normal oxide and peroxides of sodium is respectively:
🟦 A) NaO₂, Na₂O
🟩 B) Na₂O₂, Na₂O
🟪 C) Na₂O, NaO₂
🟨 D) Na₂O, Na₂O₂
3️⃣9️⃣ The chemical formula of normal oxide and superoxides of potassium is respectively:
🟦 A) K₂O, KO₂
🟩 B) K₂O₂, K₂O
🟪 C) KO, KO₂
🟨 D) KO₂, K₂O
4️⃣0️⃣ Which one of the following elements will NOT form peroxides?
🟦 A) Na
🟩 B) Sr
🟪 C) Li
🟨 D) Ba
4️⃣1️⃣ Which one of the following will form normal oxides?
🟦 A) K
🟩 B) Cs
🟪 C) Be
🟨 D) Rb
4️⃣2️⃣ Which one of the following elements will not form superoxides?
🟦 A) K
🟩 B) Cs
🟪 C) Li
🟨 D) Rb
4️⃣3️⃣ Which of the following alkali metals imparts no color to the flame?
🟦 A) Be
🟩 B) Mg
🟪 C) Both of them
🟨 D) Cs
4️⃣4️⃣ On heating sodium carbonate (Na₂CO₃), …………. is evolved:
🟦 A) CO₂ gas
🟩 B) CO gas
🟪 C) NO gas
🟨 D) Water vapours
4️⃣5️⃣ Which one of the following is the formula of peroxides of alkali metals (M)?
🟦 A) MO₂
🟩 B) M₂O₂
🟪 C) MO
🟨 D) M₂O
4️⃣6️⃣ The oxide of beryllium is:
🟦 A) Basic
🟩 B) Acidic
🟪 C) Neutral
🟨 D) Amphoteric
4️⃣7️⃣ Which is the most abundant alkali metal in earth’s crust?
🟦 A) Li
🟩 B) Na
🟪 C) K
🟨 D) Cs
4️⃣8️⃣ Which of the following alkali metals is the most electropositive with the largest atomic radius?
🟦 A) Li
🟩 B) Cs
🟪 C) K
🟨 D) Na
4️⃣9️⃣ Which of the following hydroxides is NOT amphoteric?
🟦 A) Al(OH)₃
🟩 B) Mg(OH)₂
🟪 C) Be(OH)₂
🟨 D) Zn(OH)₂
5️⃣0️⃣ The lowest melting point (29ºC) among alkali metals is for:
🟦 A) Cesium
🟩 B) Rubidium
🟪 C) Potassium
🟨 D) Lithium
5️⃣1️⃣ Which of the following is the crystal carbonate or natron?
🟦 A) Na₂CO₃
🟩 B) Na₂CO₃·10H₂O
🟪 C) NaHCO₃
🟨 D) Na₂CO₃·H₂O
5️⃣2️⃣ The formula of bleaching powder is:
🟦 A) HOCl
🟩 B) Ca(OCl)₂
🟪 C) CaOCl₂
🟨 D) None of them
5️⃣3️⃣ The flame color of which of the following alkali metals is violet?
🟦 A) Na
🟩 B) K
🟪 C) Rb
🟨 D) Cs
5️⃣4️⃣ Sodium hydroxide is used as a precipitating agent in qualitative salt analysis to precipitate heavy metal cations from their salt solutions as hydroxides. Which type of precipitated hydroxides redissolve in excess of sodium hydroxide solution?
🟦 A) Basic
🟩 B) Acidic
🟪 C) Amphoteric
🟨 D) None of them
5️⃣5️⃣ In Castner-Kellner’s process, which ions are easily discharged over moving mercury cathode?
🟦 A) H⁺
🟩 B) Na⁺
🟪 C) Both of them
🟨 D) None of them
5️⃣6️⃣ The flame color of which of the following alkali metals is red violet?
🟦 A) Na
🟩 B) K
🟪 C) Rb
🟨 D) Cs
5️⃣7️⃣ The flame color of cesium is:
🟦 A) Violet
🟩 B) Red Violet
🟪 C) Crimson Red
🟨 D) Blue Violet
5️⃣8️⃣ The flame color of lithium is:
🟦 A) Blue Violet
🟩 B) Red Violet
🟪 C) Violet
🟨 D) Crimson Red
5️⃣9️⃣ Which elements have the largest atomic radii of all the elements in their respective periods?
🟦 A) Halogens
🟩 B) Alkaline earth metals
🟪 C) Alkali metals
🟨 D) Chalcogens
6️⃣0️⃣ Which element in group IIIA does not follow the normal group trend of atomic radii?
🟦 A) B
🟩 B) Al
🟪 C) Ga
🟨 D) In
6️⃣1️⃣ Gallium has slightly smaller atomic radii than aluminium despite being placed below it in the group. This is because poor shielding effect caused by electrons of:
🟦 A) s-orbitals
🟩 B) f-orbitals
🟪 C) p-orbitals
🟨 D) d-orbitals
6️⃣2️⃣ The ionization energy (IE) of the elements of Boron family of group IIIA shows:
🟦 A) Regular trend
🟩 B) Irregular trend
🟪 C) Normal trend
🟨 D) No trend
6️⃣3️⃣ The anomalous IE trend in group IIIA has been observed between:
🟦 A) Al and Ga
🟩 B) Indium and thallium
🟪 C) Both of them
🟨 D) None of them
6️⃣4️⃣ The anomalous IE trend in group IIIA has been observed between Al and Ga and between indium and thallium. The reason for the irregularities in these two positions is due to the:
🟦 A) Poor shielding effect
🟩 B) Good shielding effect
🟪 C) Both of them
🟨 D) None of them
6️⃣5️⃣ Ga shows an unexpectedly higher IE compared to Al due to the poor shielding of nuclear charge by:
🟦 A) 3d electrons
🟩 B) 4d electrons
🟪 C) 4f electrons
🟨 D) 5f electrons
6️⃣6️⃣ Thallium exhibits an unexpectedly higher IE than indium due to the poor shielding of nuclear charge by:
🟦 A) 3d electrons
🟩 B) 4d electrons
🟪 C) 4f electrons
🟨 D) 5f electrons
6️⃣7️⃣ The anomalous or irregular IE trend in group IVA has been observed between:
🟦 A) Tin and lead
🟩 B) Ge and Sn
🟪 C) Si and Ge
🟨 D) All of them
6️⃣8️⃣ The anomalous IE trend in group IVA has been observed between tin and lead due to their almost same atomic radii because of:
🟦 A) Actinide Contraction
🟩 B) Lanthanide contraction
🟪 C) Both of them
🟨 D) None of them
6️⃣9️⃣ Which one of the following elements is/are metalloids?
🟦 A) B
🟩 B) Si
🟪 C) Ge
🟨 D) All of them
7️⃣0️⃣ Which one of the following elements is/are metalloids?
🟦 A) As
🟩 B) Sb
🟪 C) Te
🟨 D) All of them
7️⃣1️⃣ Which element of group IVA is a semi-conductor?
🟦 A) C
🟩 B) Si
🟪 C) Ge
🟨 D) Both B and C
7️⃣2️⃣ Which element of group VA is a semi-conductor?
🟦 A) As
🟩 B) Sb
🟪 C) Te
🟨 D) All of them
7️⃣3️⃣ The element with the highest boiling and melting points in group IA is:
🟦 A) Cs
🟩 B) Na
🟪 C) Li
🟨 D) K
7️⃣4️⃣ The element with the highest boiling and melting points in group IIA is:
🟦 A) Ba
🟩 B) Be
🟪 C) Ca
🟨 D) Mg
7️⃣5️⃣ In group IVA, which element shows the lowest melting point?
🟦 A) Tin
🟩 B) C
🟪 C) Si
🟨 D) Pb
7️⃣6️⃣ The flame color of barium is:
🟦 A) Violet
🟩 B) Brick red
🟪 C) Apple green
🟨 D) Crimson red
7️⃣7️⃣ In the upper part of Castner-Kellner cell, there are vertical titanium blocks immersed in an aqueous solution of sodium chloride acting as:
🟦 A) Anode
🟩 B) Cathode
🟪 C) Denuder
🟨 D) Both B and C
7️⃣8️⃣ The upper part of the Castner-Kellner cell is connected to the lower part by a graphite made chamber known as:
🟦 A) Anode
🟩 B) Cathode
🟪 C) Denuder
🟨 D) Both B and C
7️⃣9️⃣ The part of Castner-Kellner cell where the separation of sodium from amalgam takes place is:
🟦 A) Denuder
🟩 B) Cathode
🟪 C) Anode
🟨 D) Both B and C
8️⃣0️⃣ The aqueous solution of sodium chloride in the upper portion of Castner-Kellner cell mainly consists of:
🟦 A) Sodium ions (Na⁺)
🟩 B) Chloride ions (Cl⁻)
🟪 C) Hydrogen ions (H⁺)
🟨 D) Both A and B
8️⃣1️⃣ In the upper portion of Castner-Kellner cell, OH⁻ ions of water in low quantities are also oxidized to oxygen gas and water on:
🟦 A) Titanium anode
🟩 B) Titanium cathode
🟪 C) Mercury cathode
🟨 D) Denuder
8️⃣2️⃣ In Castner-Kellner cell, Na⁺ ions are discharged or reduced at the:
🟦 A) Titanium anode
🟩 B) Titanium cathode
🟪 C) Mercury cathode
🟨 D) Denuder
8️⃣3️⃣ The melting point of sodium hydroxide is:
🟦 A) 118°C
🟩 B) 218°C
🟪 C) 338°C
🟨 D) 318°C
8️⃣4️⃣ The density of 50% concentration of sodium hydroxide at room temperature is:
🟦 A) 1.52 g/cm³
🟩 B) 1.84 g/cm³
🟪 C) 2.52 g/cm³
🟨 D) 1.67 g/cm³
8️⃣5️⃣ Zinc metal reacts with aqueous solution of sodium hydroxide to liberate hydrogen gas along with:
🟦 A) Zinc chloride
🟩 B) Sodium aluminate
🟪 C) Sodium zincate
🟨 D) Zinc oxide
8️⃣6️⃣ Aluminium metal reacts with aqueous solution of sodium hydroxide to liberate hydrogen gas along with:
🟦 A) Sodium zincate
🟩 B) Sodium aluminate
🟪 C) Zinc chloride
🟨 D) Zinc oxide
8️⃣7️⃣ Which one of the following is the correct formula of sodium aluminate?
🟦 A) NaAlO₂
🟩 B) Na₂ZnO₂
🟪 C) NaAlO₃
🟨 D) Na₂AlO₂
8️⃣8️⃣ With cold-dilute and hot-concentrated solution of sodium hydroxide, chlorine undergoes:
🟦 A) Auto-redox reaction
🟩 B) Disproportionation reaction
🟪 C) Redox reaction
🟨 D) Both A and B
8️⃣9️⃣ Bleaching powder is chemically called:
🟦 A) Calcium Chlorochlorite
🟩 B) Calcium Chlorohypochlorite
🟪 C) Both of them
🟨 D) Calcium oxychloride
9️⃣0️⃣ The chemical formula of bleaching powder is:
🟦 A) Ca(OCl)Cl
🟩 B) CaOCl₂
🟪 C) Both of them
🟨 D) Ca(OCl)₂
9️⃣1️⃣ The chemical formula of bleaching powder is suggested by:
🟦 A) Professor Odling
🟩 B) Hasenclever
🟪 C) Ostwald
🟨 D) Moseley
9️⃣2️⃣ Elements of group IIIA react with oxygen to form normal oxides of the formula:
🟦 A) M₃O₄
🟩 B) M₂O₃
🟪 C) M₂O
🟨 D) MO₂
9️⃣3️⃣ The formula of boron trioxide is:
🟦 A) B₂O₄
🟩 B) B₃O₄
🟪 C) B₂O₂
🟨 D) B₂O₃
9️⃣4️⃣ The oxide of boron is ……….. in nature:
🟦 A) Neutral
🟩 B) Amphoteric
🟪 C) Basic
🟨 D) Acidic
9️⃣5️⃣ The oxide of aluminum is ……….. in nature:
🟦 A) Amphoteric
🟩 B) Basic
🟪 C) Acidic
🟨 D) Neutral
9️⃣6️⃣ In group IVA, which element can form both monoxide and dioxide?
🟦 A) Carbon
🟩 B) Si
🟪 C) Both of them
🟨 D) None of them
9️⃣7️⃣ The carbon monoxide is a/an:
🟦 A) Neutral oxide
🟩 B) Acidic oxide
🟪 C) Amphoteric oxide
🟨 D) Basic oxide
9️⃣8️⃣ Both carbon dioxide and silicon dioxide are:
🟦 A) Neutral oxides
🟩 B) Acidic oxides
🟪 C) Amphoteric oxides
🟨 D) Basic oxides
9️⃣9️⃣ In group VA, which element forms a variety of oxides?
🟦 A) Nitrogen
🟩 B) Phosphorus
🟪 C) Arsenic
🟨 D) Bismuth
1️⃣0️⃣0️⃣ Which oxide of nitrogen is neutral?
🟦 A) NO
🟩 B) N₂O
🟪 C) Both of them
🟨 D) NO₂
✅ Answers & Explanations:
1️⃣0️⃣1️⃣ Which oxide of nitrogen is acidic?
🟦 A) NO₂
🟩 B) NO
🟪 C) N₂O
🟨 D) None of them
1️⃣0️⃣2️⃣ In limited supply of oxygen, Phosphorus may form:
🟦 A) P₂O₃
🟩 B) P₂O₅
🟪 C) Both of them
🟨 D) None of them
1️⃣0️⃣3️⃣ In a sufficient supply of oxygen, Phosphorus may form:
🟦 A) P₂O₃
🟩 B) P₂O₅
🟪 C) Both of them
🟨 D) None of them
1️⃣0️⃣4️⃣ The formula of nitric oxide is:
🟦 A) NO
🟩 B) N₂O
🟪 C) N₂O₄
🟨 D) NO₂
1️⃣0️⃣5️⃣ The chemical formula of nitrous oxide is:
🟦 A) NO
🟩 B) N₂O
🟪 C) N₂O₄
🟨 D) NO₂
1️⃣0️⃣6️⃣ The chemical formula of laughing gas is:
🟦 A) NO
🟩 B) N₂O
🟪 C) N₂O₄
🟨 D) NO₂
1️⃣0️⃣7️⃣ Which one of the following is a/are sesquioxide?
🟦 A) P₂O₃
🟩 B) Al₂O₃
🟪 C) B₂O₃
🟨 D) All of them
1️⃣0️⃣8️⃣ The chemical formula of Phosphorus sesquioxide is:
🟦 A) B₂O₃
🟩 B) Al₂O₃
🟪 C) P₂O₃
🟨 D) None of them
1️⃣0️⃣9️⃣ The chemical formula of oxygen fluoride is:
🟦 A) O₂F
🟩 B) O₂F₂
🟪 C) OF₂
🟨 D) None of them
1️⃣1️⃣0️⃣ The oxide of fluorine is highly reactive:
🟦 A) Yellow gas
🟩 B) Green gas
🟪 C) Orange gas
🟨 D) None of them
1️⃣1️⃣1️⃣ Phosphorus reacts vigorously with water to produce phosphoric acid and:
🟦 A) Ammonia
🟩 B) Phosphine
🟪 C) Sulphane
🟨 D) Arsine
1️⃣1️⃣2️⃣ The chemical formula of phosphine is:
🟦 A) P₂O₃
🟩 B) PH₅
🟪 C) PCl₃
🟨 D) PH₃
1️⃣1️⃣3️⃣ The chemical formula of Diphosphane or diphosphine is:
🟦 A) P₂H₆
🟩 B) PH₃
🟪 C) P₃H₆
🟨 D) All of them
1️⃣1️⃣4️⃣ Sulphur reacts at high temperature with water to form hydrogen gas and:
🟦 A) Sulphur dioxide
🟩 B) Sulphur trioxide
🟪 C) Both of them
🟨 D) Sulphane
1️⃣1️⃣5️⃣ Which type of reactions do halogens such as chlorine and bromine undergo with water?
🟦 A) Redox reaction
🟩 B) Disproportionation
🟪 C) Auto-redox reaction
🟨 D) Both b and c
1️⃣1️⃣6️⃣ Chlorine dissolves in water to form HCl and:
🟦 A) Chlorous acid
🟩 B) Perchloric acid
🟪 C) Hypochlorous acid
🟨 D) Chloric acid
1️⃣1️⃣7️⃣ Silicon of group IVA reacts with hydrogen at high temperatures may form:
🟦 A) Methane
🟩 B) Sulphane
🟪 C) Silane
🟨 D) Silica
1️⃣1️⃣8️⃣ In group IIIA, boron and aluminium react with nitrogen to form their nitrides with general formula:
🟦 A) M₃N₄
🟩 B) M₃N₂
🟪 C) MN
🟨 D) M₃N
1️⃣1️⃣9️⃣ The chemical formula of boron nitride is:
🟦 A) B(NO₂)₃
🟩 B) B₃N₃
🟪 C) B(NO₃)₃
🟨 D) BN
1️⃣2️⃣0️⃣ In group IVA, carbon and silicon form nitrides when heated with nitrogen at high temperatures with general formula:
🟦 A) MN
🟩 B) M₃N₂
🟪 C) M₃N₄
🟨 D) M₃N
1️⃣2️⃣1️⃣ The chemical formula of carbon nitride is:
🟦 A) C₃N₂
🟩 B) C₄N₃
🟪 C) C₂N₃
🟨 D) C₃N₄
1️⃣2️⃣2️⃣ In group VA, phosphorus reacts with nitrogen at high temperature to form phosphorus nitride with chemical formula:
🟦 A) P₅N₃
🟩 B) P₃N₅
🟪 C) P₃N₃
🟨 D) P₂N₅
1️⃣2️⃣3️⃣ Halogens like Cl₂ and Br₂ react with nitrogen to form halides with general formula:
🟦 A) N₂X₃
🟩 B) NX₅
🟪 C) NX₃
🟨 D) N₂X₅
1️⃣2️⃣4️⃣ Majority of p-block elements except group IIIA and IVA react with hydrogen at high temperatures to form respective:
🟦 A) Covalent hydrides
🟩 B) Metallic hydrides
🟪 C) Complex hydrides
🟨 D) Ionic hydrides
1️⃣2️⃣5️⃣ The chemical formula of Hypobromous acid is:
🟦 A) HBrO₃
🟩 B) HBrO₂
🟪 C) HOBr
🟨 D) HBrO₄
1️⃣2️⃣6️⃣ The highest bond enthalpy among halogens is for:
🟦 A) Cl
🟩 B) Br
🟪 C) I
🟨 D) F
1️⃣2️⃣7️⃣ The bond enthalpy of fluorine is anomalously less than expected. This is due to the:
🟦 A) Inter-electronic repulsion
🟩 B) Small size
🟪 C) Both of them
🟨 D) None of them
1️⃣2️⃣8️⃣ The acidity of hydrogen halides, HX (strong mineral acids) increases from:
🟦 A) HI to HF
🟩 B) HF to HI
🟪 C) HF to HBr
🟨 D) HCl to HI
1️⃣2️⃣9️⃣ The only weak acid among halogen acids is:
🟦 A) HF
🟩 B) HCl
🟪 C) HBr
🟨 D) HI
1️⃣3️⃣0️⃣ The order of acidic strength of halogen acids is:
🟦 A) HF < HCl < HBr < HI
🟩 B) HI < HCl < HBr < HF
🟪 C) HCl < HF < HI < HBr
🟨 D) None of them
1️⃣3️⃣1️⃣ The halogen acid with least bond enthalpy is:
🟦 A) HF
🟩 B) HCl
🟪 C) HBr
🟨 D) HI
1️⃣3️⃣2️⃣ The bond enthalpy in kJ/mol of HF is:
🟦 A) 565
🟩 B) 432
🟪 C) 940
🟨 D) 645
1️⃣3️⃣3️⃣ The bond enthalpy in kJ/mol of HI is:
🟦 A) 299
🟩 B) 366
🟪 C) 432
🟨 D) 565
1️⃣3️⃣4️⃣ The oxidizing strength of halogens ………… from top to bottom in group VIIA:
🟦 A) Decreases
🟩 B) Increases
🟪 C) Remains constant
🟨 D) Unpredictable
1️⃣3️⃣5️⃣ Halogens are good oxidizing agents due to their:
🟦 A) High electronegativity
🟩 B) Ability to readily accept electrons
🟪 C) High electron affinity
🟨 D) All of them
1️⃣3️⃣6️⃣ Fluorine is the strongest agent due to its:
🟦 A) Highest electronegativity
🟩 B) Smallest atomic size
🟪 C) Ability to readily accept electrons
🟨 D) All of them
1️⃣3️⃣7️⃣ Halide ions (F⁻, Cl⁻, Br⁻, I⁻) serve as …………… in chemical reaction:
🟦 A) Reducing agents
🟩 B) Oxidizing agents
🟪 C) Bleaching agents
🟨 D) All of them
1️⃣3️⃣8️⃣ The reducing strength of halide ions …………… from top to bottom in group VIIA:
🟦 A) Decreases
🟩 B) Increases
🟪 C) Remains constant
🟨 D) Unpredictable
1️⃣3️⃣9️⃣ The pattern of relative strength of reducing agents among halide ions is:
🟦 A) I⁻ > Br⁻ > Cl⁻ > F⁻
🟩 B) F⁻ > I⁻ > Br⁻ > Cl⁻
🟪 C) F⁻ > Cl⁻ > I⁻ > Br⁻
🟨 D) None of them
1️⃣4️⃣0️⃣ Which one of the following is the strongest reducing agent among halide ions?
🟦 A) Iodide ions
🟩 B) Bromides
🟪 C) Fluorides
🟨 D) Chlorides
1️⃣ Answer: (C) Group VIIA
➡️ Melting and boiling points of halogens decrease down the group due to the increasing size and weaker London dispersion forces.
2️⃣ Answer: (C) K
➡️ Potassium forms superoxide (KO₂) when burned in air, unlike lithium or sodium.
3️⃣ Answer: (D) M₃N₂
➡️ Alkaline earth metals form nitrides with the formula M₃N₂, as observed with magnesium and calcium.
4️⃣ Answer: (A) Na
➡️ Sodium gives a distinct yellow flame when burned, a key identifying feature.
5️⃣ Answer: (C) Potassium nitrate
➡️ Potassium nitrate (KNO₃) is commonly used in fireworks due to its oxidizing properties.
6️⃣ Answer: (C) Mercury
➡️ In the Castner-Kellner cell, mercury is used as the cathode for electrolysis of sodium chloride.
7️⃣ Answer: (A) Mg
➡️ Magnesium is the diagonal member of beryllium in the periodic table, showing similar properties.
8️⃣ Answer: (A) Catalyst poisoning
➡️ Arsenic oxide can poison the catalyst used in the contact process, which is why its removal is necessary.
9️⃣ Answer: (B) Sulphuric Acid
➡️ "Oil of vitriol" is a historical name for sulfuric acid, which is widely used in industrial processes.
🔟 Answer: (A) F₂
➡️ Fluorine (F₂) is the strongest oxidizing agent among the halogens, capable of accepting electrons easily.
1️⃣1️⃣ Answer: (A) MO
➡️ The metal with the configuration 1s² 2s² 2p⁶ 3s¹ is likely sodium (Na), which forms a normal oxide MO.
1️⃣2️⃣ Answer: (B) Mg
➡️ Lithium shares similar properties with magnesium due to their diagonal relationship in the periodic table.
1️⃣3️⃣ Answer: (B) 1s² 2s² 2p⁶ 3s¹
➡️ The diagonal member of an element with the configuration 1s² 2s² is sodium (Na), which has the configuration 1s² 2s² 2p⁶ 3s¹.
1️⃣4️⃣ Answer: (D) All of them
➡️ All these s-block elements (Li, Be, Mg) form normal oxides (e.g., Li₂O, BeO, MgO) when burned in air.
1️⃣5️⃣ Answer: (A) Li
➡️ Lithium forms only a normal oxide (Li₂O) when burned in air, unlike other alkali metals which form peroxides or superoxides.
1️⃣6️⃣ Answer: (D) MN
➡️ Alkali metals, like sodium (Na), form nitrides with the formula MN, e.g., Na₃N.
1️⃣7️⃣ Answer: (A) MN₃
➡️ Group IIIA elements (like aluminum) form nitrides with the formula MN₃, e.g., AlN.
1️⃣8️⃣ Answer: (A) IIIA
➡️ Group IIIA elements, such as boron and aluminum, form nitrides with the formula M₃N₄.
1️⃣9️⃣ Answer: (C) VA
➡️ Group VA elements, such as nitrogen, form nitrides with the formula M₃N₅.
2️⃣0️⃣ Answer: (A) IA
➡️ Alkali metals (Group IA), like potassium (K), form superoxides (KO₂) with the formula MO₂.
2️⃣1️⃣ Answer: (B) PH₃
➡️ When phosphorus reacts with water, it forms phosphine (PH₃), a colorless, toxic gas.
2️⃣2️⃣ Answer: (A) C₂H₅OM
➡️ Alkali metal alkoxides, like sodium ethoxide, follow the formula C₂H₅OM, where "M" represents the alkali metal.
2️⃣3️⃣ Answer: (C) C₂H₅OLi
➡️ Lithium ethoxide has the chemical formula C₂H₅OLi, where "C₂H₅O" is the ethoxide group and "Li" is the lithium ion.
2️⃣4️⃣ Answer: (A) Alkoxide
➡️ Alkali metals react with alcohols to liberate hydrogen gas and form alkoxide salts, like sodium ethoxide (C₂H₅ONa).
2️⃣5️⃣ Answer: (C) Alkaline
➡️ Alkali metals react with water to form alkaline solutions (e.g., NaOH), making the solution basic or alkaline.
2️⃣6️⃣ Answer: (A) K
➡️ Potassium (K) imparts a lilac color to the flame when burned, which is a characteristic of potassium salts.
2️⃣7️⃣ Answer: (B) Na
➡️ Sodium (Na) is one of the few alkali metals that can float on water, as it is less dense than water.
2️⃣8️⃣ Answer: (B) Increases
➡️ The basic strength of alkaline earth metals oxides increases from Be to Ba as you go down the group, due to the increasing size of the metal cations.
2️⃣9️⃣ Answer: (D) None of them
➡️ Cesium (Cs) is most similar to potassium (K) because both are alkali metals, not to chromium (Cr) or calcium (Ca).
3️⃣0️⃣ Answer: (A) BaSO₄
➡️ Barium sulfate (BaSO₄) is insoluble in water, while the other sulfates listed are soluble.
3️⃣1️⃣ Answer: (A) KNO₃
➡️ Chile saltpeter is also known as potassium nitrate (KNO₃), commonly used in fertilizers and fireworks.
3️⃣2️⃣ Answer: (C) AgNO₃
➡️ Lunar caustic is a common name for silver nitrate (AgNO₃), used in various chemical applications.
3️⃣3️⃣ Answer: (C) Aluminium
➡️ Aluminium is a self-protected metal because it forms a protective oxide layer (Al₂O₃) that prevents further oxidation.
3️⃣4️⃣ Answer: (B) Beryllium
➡️ Beryllium does not react with cold water or steam, unlike other alkaline earth metals such as magnesium and calcium.
3️⃣5️⃣ Answer: (A) Magnesium
➡️ Magnesium reacts with boiling water and steam to form magnesium hydroxide (Mg(OH)₂) and hydrogen gas (H₂).
3️⃣6️⃣ Answer: (D) MOH, M’(OH)₂
➡️ Alkali metals form MOH (e.g., NaOH) with water, while alkaline earth metals form M’(OH)₂ (e.g., Mg(OH)₂) with water.
3️⃣7️⃣ Answer: (B) SrO₂, SrO
➡️ Strontium forms strontium peroxide (SrO₂) and strontium oxide (SrO), depending on the conditions.
3️⃣8️⃣ Answer: (B) Na₂O₂, Na₂O
➡️ Sodium forms sodium peroxide (Na₂O₂) and sodium oxide (Na₂O) depending on the oxygen content.
3️⃣9️⃣ Answer: (A) K₂O, KO₂
➡️ Potassium forms potassium oxide (K₂O) and potassium superoxide (KO₂) when reacting with oxygen.
4️⃣0️⃣ Answer: (B) Sr
➡️ Strontium (Sr) does not form peroxides, unlike lithium (Li) and sodium (Na), which form lithium peroxide (Li₂O₂) and sodium peroxide (Na₂O₂).
4️⃣1️⃣ Answer: (C) Be
➡️ Beryllium (Be) forms a normal oxide (BeO), unlike alkali metals, which tend to form peroxides or superoxides.
4️⃣2️⃣ Answer: (C) Li
➡️ Lithium (Li) does not form superoxides, while the other alkali metals (K, Cs, Rb) can form superoxides (M0₂).
4️⃣3️⃣ Answer: (C) Both of them
➡️ Both beryllium (Be) and magnesium (Mg) do not impart color to the flame, unlike alkali metals which do.
4️⃣4️⃣ Answer: (A) CO₂ gas
➡️ When sodium carbonate (Na₂CO₃) is heated, carbon dioxide (CO₂) gas is evolved.
4️⃣5️⃣ Answer: (B) M₂O₂
➡️ The formula for peroxides of alkali metals is M₂O₂, where "M" is an alkali metal.
4️⃣6️⃣ Answer: (D) Amphoteric
➡️ Beryllium oxide (BeO) is amphoteric, meaning it can act as both an acid and a base.
4️⃣7️⃣ Answer: (B) Na
➡️ Sodium (Na) is the most abundant alkali metal in the Earth’s crust, followed by potassium (K).
4️⃣8️⃣ Answer: (B) Cs
➡️ Cesium (Cs) is the most electropositive element in the alkali metal group, with the largest atomic radius.
4️⃣9️⃣ Answer: (B) Mg(OH)₂
➡️ Magnesium hydroxide (Mg(OH)₂) is not amphoteric, unlike aluminum (Al(OH)₃), beryllium (Be(OH)₂), and zinc (Zn(OH)₂) hydroxides.
5️⃣0️⃣ Answer: (A) Cesium
➡️ Cesium (Cs) has the lowest melting point (29ºC) among the alkali metals, making it the softest and most easily melted.
5️⃣1️⃣ Answer: (B) Na₂CO₃·10H₂O
➡️ Natron is a naturally occurring mineral, a hydrated sodium carbonate (Na₂CO₃·10H₂O).
5️⃣2️⃣ Answer: (B) Ca(OCl)₂
➡️ Bleaching powder has the formula Ca(OCl)₂. It contains calcium, oxygen, and chlorine and is used as a disinfectant and bleaching agent.
5️⃣3️⃣ Answer: (B) K
➡️ Potassium (K) imparts a violet color to the flame when burned, which is characteristic of potassium salts.
5️⃣4️⃣ Answer: (C) Amphoteric
➡️ Amphoteric hydroxides, like Al(OH)₃ and Zn(OH)₂, dissolve in excess sodium hydroxide solution, forming soluble complexes.
5️⃣5️⃣ Answer: (A) H⁺
➡️ In Castner-Kellner's process, hydrogen ions (H⁺) are easily discharged over the moving mercury cathode, leading to the formation of hydrogen gas.
5️⃣6️⃣ Answer: (C) Rb
➡️ Rubidium (Rb) gives a red-violet flame color when burned, which is characteristic of rubidium salts.
5️⃣7️⃣ Answer: (D) Blue Violet
➡️ Cesium (Cs) imparts a blue-violet flame color, distinct from other alkali metals like sodium (yellow) and potassium (violet).
5️⃣8️⃣ Answer: (D) Crimson Red
➡️ Lithium (Li) gives a crimson red flame color when burned, which is characteristic of lithium salts.
5️⃣9️⃣ Answer: (C) Alkali metals
➡️ Alkali metals (group 1) have the largest atomic radii in their respective periods due to their low ionization energy and single valence electron.
6️⃣0️⃣ Answer: (A) B
➡️ Boron (B) does not follow the usual trend of atomic radii in group IIIA. As you move down the group, the atomic radius usually increases, but boron is smaller than expected due to its high nuclear charge.
6️⃣1️⃣ Answer: (D) d-orbitals
➡️ Gallium has slightly smaller atomic radii than aluminum due to the poor shielding effect of the 3d electrons in Ga, which are less effective at shielding the nuclear charge.
6️⃣2️⃣ Answer: (B) Irregular trend
➡️ The ionization energy of the elements in group IIIA shows an irregular trend due to differences in electron configurations, especially between boron, aluminum, and gallium.
6️⃣3️⃣ Answer: (C) Both of them
➡️ The anomalous ionization energy trends are observed between both Al and Ga, as well as Indium and Thallium. This is due to variations in the shielding and electron configurations.
6️⃣4️⃣ Answer: (A) Poor shielding effect
➡️ The irregular trends in ionization energy between Al and Ga, and Indium and Thallium are primarily due to the poor shielding effect of the d-orbitals and f-orbitals in these elements.
6️⃣5️⃣ Answer: (A) 3d electrons
➡️ Gallium (Ga) has an unexpectedly higher ionization energy compared to aluminum (Al) due to the poor shielding provided by the 3d electrons in Ga.
6️⃣6️⃣ Answer: (B) 4d electrons
➡️ Thallium (Tl) exhibits higher ionization energy than Indium (In) due to the poor shielding effect of the 4d electrons in Thallium.
6️⃣7️⃣ Answer: (A) Tin and lead
➡️ The anomalous ionization energy trend in group IVA is observed between tin (Sn) and lead (Pb) due to their almost identical atomic radii caused by lanthanide contraction.
6️⃣8️⃣ Answer: (B) Lanthanide contraction
➡️ The similar atomic radii of tin (Sn) and lead (Pb) is due to the lanthanide contraction, which occurs because of the poor shielding effect of the f-electrons in the lanthanide series.
6️⃣9️⃣ Answer: (D) All of them
➡️ Boron (B), Silicon (Si), and Germanium (Ge) are all considered metalloids, exhibiting both metallic and non-metallic properties.
7️⃣0️⃣ Answer: (D) All of them
➡️ Arsenic (As), Antimony (Sb), and Tellurium (Te) are all metalloids, positioned along the "staircase" line of the periodic table.
7️⃣1️⃣ Answer: (D) Both B and C
➡️ Silicon (Si) and Germanium (Ge) are both semiconductors, making them suitable for use in electronic devices.
7️⃣2️⃣ Answer: (D) All of them
➡️ Arsenic (As), Antimony (Sb), and Tellurium (Te) are all semiconductors, and are commonly used in electronics.
7️⃣3️⃣ Answer: (C) Li
➡️ Lithium (Li) has the highest melting and boiling points in group IA due to its small atomic size and strong metallic bonding.
7️⃣4️⃣ Answer: (B) Be
➡️ Beryllium (Be) has the highest melting and boiling points in group IIA because of its strong covalent bonding and small atomic size.
7️⃣5️⃣ Answer: (D) Pb
➡️ Lead (Pb) in group IVA has the lowest melting point due to its relatively weak metallic bonds compared to the other elements in the group.
7️⃣6️⃣ Answer: (C) Apple Green
➡️ Barium (Ba) gives an apple green flame color when burned, which is distinctive of barium salts.
7️⃣7️⃣ Answer: (A) Anode
➡️ The vertical titanium blocks in the upper part of the Castner-Kellner cell act as the anode.
7️⃣8️⃣ Answer: (C) Denuder
➡️ The upper and lower parts of the Castner-Kellner cell are connected by a graphite chamber known as the denuder, which helps separate sodium from amalgam.
7️⃣9️⃣ Answer: (A) Denuder
➡️ Sodium separation from amalgam occurs in the denuder of the Castner-Kellner cell.
8️⃣0️⃣ Answer: (D) Both A and B
➡️ The aqueous solution of sodium chloride in the upper portion of the Castner-Kellner cell consists mainly of sodium ions (Na⁺) and chloride ions (Cl⁻).
8️⃣1️⃣ Answer: (A) Titanium anode
➡️ At the titanium anode, OH⁻ ions in water are oxidized to form oxygen gas and water.
8️⃣2️⃣ Answer: (C) Mercury cathode
➡️ Sodium ions (Na⁺) are reduced at the mercury cathode, forming sodium amalgam.
8️⃣3️⃣ Answer: (C) 338°C
➡️ Sodium hydroxide has a melting point of 338°C, which is high compared to many other alkali hydroxides.
8️⃣4️⃣ Answer: (B) 1.84 g/cm³
➡️ The density of a 50% concentration of sodium hydroxide at room temperature is 1.84 g/cm³.
8️⃣5️⃣ Answer: (C) Sodium zincate
➡️ When zinc reacts with sodium hydroxide, sodium zincate is formed along with hydrogen gas.
8️⃣6️⃣ Answer: (B) Sodium aluminate
➡️ When aluminum reacts with sodium hydroxide, sodium aluminate is formed along with hydrogen gas.
8️⃣7️⃣ Answer: (A) NaAlO₂
➡️ The correct formula for sodium aluminate is NaAlO₂, which is used in various industrial processes.
8️⃣8️⃣ Answer: (D) Both A and B
➡️ Chlorine undergoes both auto-redox and disproportionation reactions in the presence of sodium hydroxide.
8️⃣9️⃣ Answer: (C) Both of them
➡️ Bleaching powder is commonly known as both calcium chlorochlorite and calcium chlorohypochlorite, depending on the source.
9️⃣0️⃣ Answer: (B) CaOCl₂
➡️ The chemical formula of bleaching powder is CaOCl₂, used as a disinfectant and in bleaching applications.
9️⃣1️⃣ Answer: (A) Professor Odling
➡️ Professor Odling is credited with suggesting the chemical formula of bleaching powder as Ca(OCl)₂.
9️⃣2️⃣ Answer: (B) M₂O₃
➡️ Group IIIA elements like Boron (B), Aluminium (Al), etc., react with oxygen to form normal oxides with the general formula M₂O₃.
9️⃣3️⃣ Answer: (D) B₂O₃
➡️ The formula of boron trioxide is B₂O₃, which is commonly found in boric acid and used in the production of glasses.
9️⃣4️⃣ Answer: (B) Amphoteric
➡️ Boron oxide (B₂O₃) is amphoteric in nature, meaning it can react with both acids and bases.
9️⃣5️⃣ Answer: (A) Amphoteric
➡️ Aluminum oxide (Al₂O₃) is amphoteric, meaning it can react with both acids and bases.
9️⃣6️⃣ Answer: (C) Both of them
➡️ Both Carbon (C) and Silicon (Si) can form monoxide (CO, SiO) and dioxide (CO₂, SiO₂).
9️⃣7️⃣ Answer: (A) Neutral oxide
➡️ Carbon monoxide (CO) is considered a neutral oxide because it does not exhibit acidic or basic behavior.
9️⃣8️⃣ Answer: (B) Acidic oxides
➡️ Both carbon dioxide (CO₂) and silicon dioxide (SiO₂) are acidic oxides, meaning they form acids when dissolved in water.
9️⃣9️⃣ Answer: (B) Phosphorus
➡️ Phosphorus can form a wide variety of oxides, such as P₄O₆, P₄O₁₀, and others, depending on the oxidation state.
1️⃣0️⃣0️⃣ Answer: (C) Both of them
➡️ Both Nitric Oxide (NO) and Dinitrogen monoxide (N₂O) are neutral oxides of nitrogen.
1️⃣0️⃣1️⃣ Answer: (A) NO₂
➡️ Nitrogen dioxide (NO₂) is an acidic oxide. It dissolves in water to form nitric acid (HNO₃), which makes it acidic.
1️⃣0️⃣2️⃣ Answer: (A) P₂O₃
➡️ In limited oxygen supply, phosphorus forms phosphorus trioxide (P₂O₃), which is a common oxide in such conditions.
1️⃣0️⃣3️⃣ Answer: (B) P₂O₅
➡️ In a sufficient supply of oxygen, phosphorus forms phosphorus pentoxide (P₂O₅), which is an acidic oxide.
1️⃣0️⃣4️⃣ Answer: (A) NO
➡️ Nitric oxide (NO) has the formula NO. It is a colorless gas that reacts with oxygen to form NO₂.
1️⃣0️⃣5️⃣ Answer: (B) N₂O
➡️ Nitrous oxide (N₂O), commonly known as laughing gas, has the chemical formula N₂O.
1️⃣0️⃣6️⃣ Answer: (B) N₂O
➡️ Laughing gas is nitrous oxide (N₂O), which is a colorless, sweet-smelling gas used in various applications, including as an anesthetic.
1️⃣0️⃣7️⃣ Answer: (A) P₂O₃
➡️ Phosphorus trioxide (P₂O₃) is a sesquioxide, meaning it has the formula M₂O₃ (where M is the element).
1️⃣0️⃣8️⃣ Answer: (C) P₂O₃
➡️ Phosphorus sesquioxide is phosphorus trioxide (P₂O₃), which is formed when phosphorus reacts with limited oxygen.
1️⃣0️⃣9️⃣ Answer: (C) OF₂
➡️ Oxygen difluoride (OF₂) is the chemical formula for oxygen fluoride, a highly reactive compound formed by the direct reaction of oxygen and fluorine.
1️⃣1️⃣0️⃣ Answer: (B) Green gas
➡️ Oxygen fluoride (OF₂) is a highly reactive green gas and is one of the few compounds in which oxygen has a negative oxidation state.
1️⃣1️⃣1️⃣ Answer: (B) Phosphine
➡️ When phosphorus reacts with water, it produces phosphoric acid (H₃PO₄) and phosphine (PH₃), which is a highly toxic and flammable gas.
1️⃣1️⃣2️⃣ Answer: (D) PH₃
➡️ Phosphine (PH₃) is a colorless, flammable, and toxic gas that is similar to ammonia in chemical behavior.
1️⃣1️⃣3️⃣ Answer: (A) P₂H₆
➡️ Diphosphane (P₂H₆), also known as diphosphine, is a molecule made of two phosphorus atoms and six hydrogen atoms.
1️⃣1️⃣4️⃣ Answer: (A) Sulphur dioxide
➡️ Sulfur reacts with water to form hydrogen sulfide gas (H₂S) and sulfur dioxide (SO₂), which is often released during such reactions.
1️⃣1️⃣5️⃣ Answer: (D) Both b and c
➡️ Halogens like chlorine and bromine undergo disproportionation reactions with water, meaning they are both reduced and oxidized in the process. Hence, they also experience auto-redox reactions.
1️⃣1️⃣6️⃣ Answer: (C) Hypochlorous acid
➡️ Chlorine dissolves in water to form hypochlorous acid (HOCl), which is responsible for chlorine's disinfectant properties in swimming pools and bleach.
1️⃣1️⃣7️⃣ Answer: (C) Silane
➡️ Silicon reacts with hydrogen at high temperatures to form silane (SiH₄), a compound that is similar to methane (CH₄) but with silicon replacing carbon.
1️⃣1️⃣8️⃣ Answer: (C) MN
➡️ Boron and aluminum react with nitrogen to form their respective nitrides, such as aluminum nitride (AlN) and boron nitride (BN), both with the general formula MN.
1️⃣1️⃣9️⃣ Answer: (D) BN
➡️ Boron nitride has the formula BN. It is a compound that can exist in various forms, including hexagonal (graphite-like) and cubic (diamond-like).
1️⃣2️⃣0️⃣ Answer: (B) M₃N₂
➡️ Carbon and silicon form nitrides with the general formula M₃N₂ when heated with nitrogen, such as silicon nitride (Si₃N₄) and carbon nitride.
1️⃣2️⃣1️⃣ Answer: (A) C₃N₂
➡️ Carbon nitride (C₃N₂) is a compound formed from carbon and nitrogen, known for its high hardness and stability.
1️⃣2️⃣2️⃣ Answer: (B) P₃N₅
➡️ Phosphorus reacts with nitrogen to form phosphorus nitride (P₃N₅) at high temperatures.
1️⃣2️⃣3️⃣ Answer: (C) NX₃
➡️ Halogens such as chlorine and bromine react with nitrogen to form halides with the general formula NX₃, like nitrogen trichloride (NCl₃).
1️⃣2️⃣4️⃣ Answer: (A) Covalent hydrides
➡️ Most p-block elements react with hydrogen at high temperatures to form covalent hydrides, such as methane (CH₄), ammonia (NH₃), and water (H₂O).
1️⃣2️⃣5️⃣ Answer: (C) HOBr
➡️ Hypobromous acid has the formula HOBr and is similar to hypochlorous acid (HOCl).
1️⃣2️⃣6️⃣ Answer: (D) F
➡️ Fluorine has the highest bond enthalpy among the halogens due to its small size and strong bond.
1️⃣2️⃣7️⃣ Answer: (A) Inter-electronic repulsion
➡️ The anomalously low bond enthalpy of fluorine is due to the repulsion between the lone pairs of electrons in the small fluorine atom.
1️⃣2️⃣8️⃣ Answer: (B) HF to HI
➡️ The acidity of hydrogen halides increases from HF to HI because of the bond strength decreasing as we move down the group.
1️⃣2️⃣9️⃣ Answer: (A) HF
➡️ HF is the only weak acid among the halogen acids due to the strong bond between hydrogen and fluorine.
1️⃣3️⃣0️⃣ Answer: (A) HF < HCl < HBr < HI
➡️ The acidic strength increases from HF to HI because the bond strength decreases, making it easier to release protons.
1️⃣3️⃣1️⃣ Answer: (D) HI
➡️ HI has the least bond enthalpy, making it the weakest bond among the hydrogen halides.
1️⃣3️⃣2️⃣ Answer: (A) 565
➡️ The bond enthalpy of HF is 565 kJ/mol, which is the highest bond energy among hydrogen halides.
1️⃣3️⃣3️⃣ Answer: (A) 299
➡️ The bond enthalpy of HI is relatively low at 299 kJ/mol.
1️⃣3️⃣4️⃣ Answer: (A) Decreases
➡️ The oxidizing strength of halogens decreases as we move down the group from fluorine to iodine.
1️⃣3️⃣5️⃣ Answer: (D) All of them
➡️ Halogens are good oxidizing agents because of their high electronegativity, high electron affinity, and their ability to readily accept electrons.
1️⃣3️⃣6️⃣ Answer: (D) All of them
➡️ Fluorine is the strongest oxidizing agent due to its high electronegativity, small atomic size, and ability to readily accept electrons.
1️⃣3️⃣7️⃣ Answer: (A) Reducing agents
➡️ Halide ions (F⁻, Cl⁻, Br⁻, I⁻) serve as reducing agents by donating electrons in redox reactions.
1️⃣3️⃣8️⃣ Answer: (B) Increases
➡️ The reducing strength of halide ions increases from top to bottom in Group VIIA (fluoride to iodide).
1️⃣3️⃣9️⃣ Answer: (A) I⁻ > Br⁻ > Cl⁻ > F⁻
➡️ Iodide ions (I⁻) are the strongest reducing agents among the halides, with the strength decreasing down the group.
1️⃣4️⃣0️⃣ Answer: (A) Iodide ions
➡️ Iodide ions (I⁻) are the strongest reducing agents because they can easily donate electrons compared to other halide ions.
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