Get the X-Chemistry National Comprehensive Targeted Guess Paper 2026 for Class 10 Chemistry. Designed specially for Karachi Board students, this paper includes important MCQs, short questions, and long questions expected in the final exams 2026. Prepare smartly and score high with updated Karachi Board notes and exam tips!
1. For the reaction,
2A(g) + B(g) ⇌ 3C(g) the expression for the
equilibrium constant is:
(a) [2A][B]/[3C]
(b) [A]2[B]/[C]3
(c) [3C]/[2A][B]
(d)
[C]3/[A]2[B]
2. Equilibrium
constant value “Kc“ is equal to;
(a) Qc/Kr
(b) Kr /Kf
(c) Kc/Qc
(d) Kf/Kr
3. NH3 can
be a base according to
(a) Arrhenius theory
(b) Bronsted-Lowry theory
(c) Lewis theory
(d) both
b and c
4. Which
of the following is a Lewis base?
(a) HNO3
(b) AlCl3
(c) HCl
(d) CN−
5. The
general formula of alkynes is
(a) CnH2n
(b) CnH2n+1
(c) CnH2n–2
(d) CnH2n+2
6. Which
of the following is an alcohol?
(a) CH3CHO
(b) CH3CH2OCH3
(c) CH3CH2OH
(d) HCOOH
7. Which one of the
following is polysaccharide?
(a) Fructose
(b) maltose
(c) starch
(d) None
8. cellulose content in Cotton is
(a) 70%
(b) 95%
(c ) 85%
(d) 90%
9. Ozone layer is
part of
(a) stratosphere
(b) mesosphere
(c) thermosphere
(d) troposphere
10. It used to assess concentration
or amount of given atomic, molecular or ionic chemical.
(a) Chromatography
(b) Spectroscopy
(c) Conductometry
(d) Potentiometry
11. Surfactants reduce the......... of water.
(a) Surface tension
(b) Viscosity
(c) Boiling point
(d)
Melting point
12. The centrifuge machine used for separation of:
(a) Crystal
(b) pH
(c) Mud
(d) Juice
13. Insulin which enables our body to use glucose obtained
from food or glycogen is basically:
(a) an enzyme
(b) a hormone
(c) an starch
(d) a mineral
14. Vital force theory was introduced by
(a) Robert Boyle
(b) J. J. Berzelius
(c) Lewis
(d) Wohler
15. Lactose enzymes are used:
(a) in production of bread
(b) to make ice cream sweeter
(c) to make alcohol
(d) to maintain colour
1. Define any three of the following:
equilibrium
constant, reaction quotient, extent of a reaction, pH, Indicator, Neutralization,
Titration, alicyclic compounds, aromatic compounds,
catenation, aldoses, ketoses, saccharides, functional group, Peptide linkage, saponification, lipids, enzymes, isomerism,
Bloor’s reagent, fatty acid, ozone hole, organic chemistry, Biochemistry, Environmental chemistry, Analytical Chemistry,
Qualitative Analysis, Quantitative Analysis, accuracy, precision, titrant,
analyte, Indicator, parameter
2. Write down three differences between any one of
the following:
(i) Troposphere and Stratosphere
(ii) reversible and irreversible reactions
(iii) saturated and unsaturated hydrocarbons
(iv) Dextrorotary and Levorotatory Sugars
(v) Quantitative analysis and qualitative analysis
(vi) Titrimetric analysis and gravimetric analysis
(vii) Classical and Instrumental Methods
(viii) fat and water-soluble vitamins.
(ix) DNA and RNA
(x)
fat and oil
(xi) Aldoses and ketoses
3. Define chemical equilibrium
state. Why chemical equilibrium is dynamic? Explain it with one example.
OR
Describe the characteristics of
equilibrium constant. Why equilibrium constant may or may not have unit?
Justify with example.
4. Write down Equilibrium Constant Expression (Kc)
and unit of Kc for any 3 of the following balanced reversible reactions.
(i) N2(g) + 2O2(g) ⇌ 2NO2(g)
(ii) H2(g) + I2(g) ⇌ 2HI(g)
(iii) CO2(g) + H2(g) ⇌ CO(g) + H2O(g)
(iv) 2SO2(g) + O2(g) ⇌ 2SO3(g)
(v) N2(g) + 3H2(g) ⇌ 2NH3(g)
(vi) CO(g) + 3H2(g) ⇌ CH4(g) + H2O(g)
6. State vital force theory and how was this
theory discarded by Wohler?
Or
Write the names and structural formulae of
six carbons alkanes, alkenes, alkyne, cycloalkane and aromatic hydrocarbons.
OR
Draw the
structures of following compounds:
(i) 2,3-dimethylpentane
(ii) 3-ethyl-1-hexene
(iii) 2-butyne
(iv)
2,4-hexadiene
(v) 3-methyl-1,4-hexadiyne
(vi) 2-hepten-5-yen
(vii) 2-pentyne
(viii) neopentane
(ix) iso-propyl alcohol
(x) Phenol or toluene
(xi) iso-butane
(xii) Cyclohexane
8. Define salt
and its three types with two examples each. Give three uses of salts. Also
write any three methods of
preparation of salts with equation.
OR Write
one use of enzymes yeast, cellulase and amylase.
OR What is homologous series? Name the any two
common homologous series with examples. Write down the general characteristics of homologous series.
OR
What
is alkyl radicals? Give its type formula and general formula. Explain with
structure different radicals of butane.
What is the difference of alkyl radicals obtained from propane?
9. Elaborate
ionization equation of water. Explain in detail that how water ionization is
related with pH of solution?
OR
Define buffers. What is the composition of buffers? Discuss its importance in
our daily life.
10. Write any
three significant uses of Carbohydrates and lipids.
OR
What are amino acids and peptide bond? How peptide bond is formed? Also explain
dipeptides & tripeptides.
11. Give
reason:
(i) Why Silicon compounds are lesser than that of Carbon compounds?
(ii) Why pure water is considered as weak electrolyte?
(iii) Justify the petroleum is ‘black gold’.
(iv) Alkanes are said to be saturated hydrocarbons.
(v) Justify that water soluble vitamins are not injurious to health.
(vi) Justify that greenhouse effect leads to global warming
(vii) Justify that “water is solvent”.
(viii) How is vegetable oil is converted into saturated fat (ghee)?
(ix) Why chemical equilibrium is considered dynamic not static?
(x) Why the temperature on top of a mountain is colder than at sea level?
13. What
are Oligosaccharides, Disaccharides and polysaccharides. Give their examples
and sources.
OR
What are the
carbohydrates? Explain sources and types of carbohydrates.
14. What are
amino acids and give their general structure? How many Essential and
Non-essential Amino acids are there? Write down the range of Number
of Amino acids and molecular
weights of Proteins
OR
What are fatty acids? Give
their examples and chemical nature.
15. Briefly
describe any three beneficial impacts of pharmaceutical industry on human
society.
16.
Write down causes of following
diseases:
(i) Diarrheal Diseases
(ii) Dysentery
(iii) Cholera
(iv) Crytosporidium
(v) Fluorosis
(vi) Hepatitis
(vii) Hookworm
(viii) Typhoid
17. What is
the cause of acid rain? Explain. Write down the effects of acid rain and global
warming.
OR
What are primary and
secondary air pollutants? Or Give difference between primary and secondary air pollutants. Identify as primary or
secondary air pollutant SO2, CH4, HNO3, NH3,
H2SO4 and O3
18. Describe
the composition of water. Write degree of Hardness
of water on the basis of Dissolved Ca Ions (mg/L)
19. List down
the applications of conductometry?
OR
Describe the
composition of water. Write down degree of Hardness of water on the basis
of Dissolved Ca Ions.
20. What is error? Write down causes of errors with their %. Write down brief note systematic and random errors with two examples each.
OR
Describe fractional distillation of petroleum with
its 5 fractions.
21. A solution of HCl has pH of 2.3.
Calculate its pOH and [H+]?
OR
Find pH, pOH, [OH−] and [H+] of 2.46 × 10−9 M KOH solution.
22. State law of mass action and define Kc. Derive an expression
for equilibrium constant for a general reaction.
23. State and explain
Bronsted-Lowry acid-base theory or Lewis concept of acids and bases with
examples? explain with an example that water is a Bronsted-Lowry
acid as well as Bronsted-Lowry base. OR
State three different theories about concepts of acids and
bases with one example and also indicate one limitation
of each concept. Which of the following is/are Arrhenius acids and bases?
(a) Ca(OH)2 (b)
HNO3 (c)
NaOH (d) H2SO4
(e) KOH
24. Define
functional group. Write different functional groups which contain carbon,
hydrogen and oxygen.
OR
Define
nomenclature and describe IUPAC nomenclature rules for alkynes and alkanes. Write
down IUPAC names of following:
25. What are the
main sources of organic compounds? Mention with special reference of coal,
petroleum and natural gas.
OR
What do you mean by diversity and magnitude
of organic compounds? Give at least 5 reasons.
26. What are Lipids?
Write down the sources and
uses of lipids. Write five
differences between Fats and Oils.
OR
What
are proteins and peptide bond? How peptide bond is formed in dipeptides and
tripeptides ? Write down the
range of Number of Amino acids
and molecular weights of Proteins. Give importance and sources of proteins.
27. Describe in detail nucleic acids, RNA and DNA. Write down importance
of deoxyribonucleic acid (DNA).
28. Describe process of Saponification with the help of
flow sheet diagram.
OR
Describe fractions of petroleum in detail.
29. Justify that electrochemical methods depend upon electrochemical
cells.
OR What is Titrimetric Analysis? Describe how it is performed
with diagram.
30. Explain the process of
preparation sugar from sugar cane. OR Describe process of Saponification with the help of
flow sheet diagram.
31. What is Ozone? How does Ozone depletion occur by
Chlorofluorocarbons (CFCs) also mention some adverse impact of it?
OR Describe global warming. Justify that greenhouse effect leads to
global warming.
32. Describe Gas Chromatography with diagram also write
two uses of gas chromatography.
33. What are Soft Water and Hard Water and describe
different methods of removing temporary and permanent hardness. Write down 5 disadvantages of hard
water.
34. Definition
Water Pollution. Write down its Causes and Effects on Life
35. For
the reaction, H2(g) + I2(g)
⇌ 2HI(g) (Kc = 57.0); the
concentrations of H2(g), I2(g) and HI(g) at
time t are:
[H2]t = 0.10 mol dm−3,
[I2]t = 0.20 mol dm−3,
[HI]t = 0.40 mol dm−3
Predict in which direction reaction will move
to achieve equilibrium.
(Answer; Qc (8.0) is less than Kc (57.0), reaction will move in the forward direction)
OR
Equilibrium
occurs when nitrogen monoxide gas reacts with oxygen gas to form nitrogen
dioxide gas
2NO(g) + O2(g) ⇌ 2NO2(g)
At equilibrium at 230oC, the concentrations are
measured to be
[NO] = 0.0542 mol dm−3,
[O2] = 0.127 mol dm−3
and
[NO2] = 15.5 mol dm−3
Calculate the equilibrium constant at this temperature. (Book problem 1; page 8)(Answer; 6.44 x 105 mol-1 dm3)
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