CHEMISTRY (GUESS PAPER)

SHORT QUESTIONS:
CHAPTER NO.1
1. Explain with reason: No individual neon atom in the sample of the element has a mass of
20.18 amu.
2. N2 and CO have the same number of electrons, protons and neutrons.
3. Justify this statement: Magnesium atom is twice heavier than that of carbon atom.
4. 23 g of sodium and 238 g of uranium have equal number of atoms in them.
5. One mg of K2CrO4 has thrice the number of ions than the number of formula units when
ionized in water.
6. Explain with reason: Many chemical reactions taking place in our surrounding involve the
limiting reactants.
7. What is stoichiometry? Write its assumptions.
8. How to identify a limiting reactant?
9. Define relative atomic mass and isotopes?
10. Define gram formula and also give two examples.
11. Differentiate between empirical formula and molecular formula.

CHAPTER NO.2
1. What do you mean by solvent extraction? Which law controls it?
2. Define chromatography. Give its two uses.
3. What is the difference between adsorption and partition chromatography?
4. Define sublimation with an example.
5. How can color impurities be removed from the product?
6. How crystals are dried by reliable method?
7. Give the salient features of an ideal solvent used in the process of crystallization.
8. Explain filtration through Gooch Crucible?
9. How does rate of filtration increased by fluted filter paper?
10. Why is there a need to crystallize the crude product?
11. What is Rf value; Also write its formula.

CHAPTER NO.3
1. Explain this statement: Water vapours do no behave ideally at 273K.
2. Explain this statement: The plot of PV versus P is a straight line at constant temperature
and with a fixed number of moles of an ideal gas.
3. Calculate the value of R at STP and in SI units.
4. Why normal air cannot be used for breathing by sea divers?
5. Derive Avogadro’s law from kinetic molecular theory of gases.
 6. Define Dalton’s law of partial pressure.
7. Write two faulty assumptions of kinetic molecular theory of gases.
8. Write down two characteristics of plasma.
9. What is plasma? Also, write its three uses.
10. What is meant by critical temperature and critical pressure?
11. Calculate the density of CH4 at 0’C and 1 atmospheric pressure?
12. Deduce Boyle’s law from KMT of gases.

CHAPTER NO.4
1. Explain with reason: Amorphous solids like glass are also called super cooled liquids.
2. Why the electrical conductivity of the metals decrease by increasing temperature?
3. What do you mean by Debye forces?
4. Explain with reason: Earthenware vessels keep water cool.
5. Explain with reason: The boiling point of water is different at Murree hills and at Mount
Everest.
6. How soaps and detergents perform the cleansing action?
7. What is the difference between isomorphism and polymorphism?
8. Define transition temperature and crystal lattice.
9. Explain with reason: Diamond is hard and an electrical insulator.
10. Why ionic crystals are highly brittle?
11. What do you mean by habit of a crystal and growing of a crystal?
12. Explain with reason: Water and ethanol can mix easily and in all proportions.
13. Boiling needs a constant supply of heat. Give reason.
14. What is polarizability? Give its relation with London dispersion force.

CHAPTER NO.5
1. Differentiate between Zeeman and Stark effect.
2. Define Moseley’s law. Also, write its importance.
3. Why is it necessary to decrease the pressure in the discharge tube to get the cathode rays?
4. The e/m value for positive rays obtained from hydrogen gas is 1836 times less than that of
cathode rays. Justify it.
5. How the bending of the cathode rays in the electric and magnetic fields shows that they are
negatively charged?
6. Prove that the total energy of the bounded electron is negative.
7. Write down any four properties of neutron.
8. Differentiate between continuous and atomic spectrum.
9. Write a note on azimuthal quantum number.
10. State Hund’s rule and (n+l) rule.
11. Name five spectral series with their regions.
12. Write down the reason for the production of positive rays.
 13. Prove that the cathode rays are material particles.
14. State Heisenberg’s uncertainty principle and give its mathematical expression.

CHAPTER NO.6
1. Why the radius of an atom cannot be determined precisely?
2. Define electronegativity and give its trend in a periodic table.
3. Differentiate between sigma and pi bond. (OR) pi bonds are more diffused than sigma
bonds. Why?
4. Explain with reason: Bond distance is the compromise distance between two atoms.
5. Why MOT is superior to VBT?
6. Why bond formation is not possible between two He atoms?
7. Explain with reason: The dipole moments of CO2 and CS2 are zero but that of SO2 is 1.61D.
8. The bond angle in NF3 is smaller than in NH3. Justify it.
9. Define ionization energy. Also, discuss it along the period within the periodic table.
10. Why the radius of Na+ ion is smaller than Na atom?

CHAPTER NO.7
1. Differentiate between spontaneous and non-spontaneous reactions.
2. Explain the burning of a candle is a spontaneous process.
3. What is system and state function? Also, write examples.
4. Define standard enthalpy of atomization with an example.
5. Prove that the change in enthalpy is equal to heat of reaction at constant pressure.
6. Define enthalpy of solution and enthalpy of combustion?
7. Define Born-Haber cycle and lattice energy.

CHAPTER NO.8
1. What is the effect of a catalyst on equilibrium constant?
2. What are the optimum conditions for the synthesis of NH3?
3. Write down any three ways to maximize the yield of ammonia?
4. Define pKa and pKb.
5. What is meant by common ion effect?
6. Differentiate between acidic and basic buffer.
7. Explain with reason: The solubility of glucose in water is increased by increasing the
temperature.
8. How equilibrium constant predicts direction of a reaction?
9. Calculate the PH of 10-4 mol dm-3 of Ba(OH)2.
10. Write down the equilibrium constant expression for the following reversible reactions: (a)
Ammonia synthesis (b) Dissociation of PCl5
11. Explain the term buffer capacity.
12. What is Le-Chatelier’s principle.
CHAPTER NO.9

1. Differentiate between ideal and non-ideal solutions.

2. Differentiate between molarity and molality.
3. What is critical solution temperature? Give one example.
4. Justify this statement: NaCl and KNO3 are used to lower the melting point of ice.
5. How do you justify that the boiling points of the solvents increase due to the presence of
solutes?
6. Explain with reason: 100 g of 98% H2SO4 has a volume of 54.34 cm3 of H2SO4. (Density=
1.84 g cm-3).
7. Define parts per million and give its expression.
8. Define Raoult’s law with two statements giving its equation.
9. Explain with reason: The concentration in terms of molality is independent of temperature
but molarity depends upon temperature.
10. Differentiate between continuous and discontinuous solubility curves.
11. Define colligative properties. Also, name of them.
12. What do you know about water of crystallization or water of hydration?

CHAPTER NO.10

1. Explain with reason: Impure Cu can be purified by electrolytic process.

2. Write down the functions of salt bridge?
3. Explain with reason: Na and K can displace hydrogen from acids but Pt, Pd and Cu cannot.
4. Explain with reason: The standard oxidation potential of Zn is +0.76V and its reduction
potential is -0.76V.
5. What is meant by standard hydrogen electrode (SHE)?
6. Write down the advantages of fuel cell?
7. Voltaic cell is a reversible cell. Explain this statement.
8. Explain the difference between electrolytic cell and voltaic cell.
9. How is anodized aluminium prepared? Give the advantages of anodization of aluminium.
10. What is the difference between primary and secondary cell?
11. Explain the nickel cadmium cell.
12. Calculate the oxidation number of sulphur in SO42- and in H2SO4.
CHAPTER NO.11

1. Explain this statement: A catalyst is specific in its action.

2. Differentiate between homogenous and heterogeneous catalysis.
3. Justify this statement: A radioactive decay is always a first order reaction.
4. What is catalytic poisoning? Give an example.
5. What is meant by zero order and pseudo first order reaction?
6. How order of a reaction can be calculated from half-life method?
7. Explain specific rate constant of a reaction.
8. Define negative catalyst with an example.
9. Give any three characteristics of enzyme catalysis.
10. Justify this statement: A finely divided catalyst may prove more effective.
11. What is activated complex?

LONG QUESTIONS

1. Explain the concept of limiting reactant with a suitable example. Also, write down the
steps to identify a limiting reactant.
2. Write a note on combustion analysis.
3. Write a note on yield.
4. Write a note on manometric method.
5. Define liquid crystals. Also, write their uses.
6. Write down the properties of ionic solids.
7. What are London forces? Write down factors affecting them.
8. Explain Millikan’s oil droplet experiment for the determination of charge on an electron.
9. Derive an expression to calculate the radius of revolving electron in the nth orbit of
hydrogen atom.
10. What is J.J. Thomson’s experiment for determining e/m value of electron?
11. What are quantum numbers? Explain principle and azimuthal quantum number in detail.
12. Draw the molecular orbital diagram for O2 and explain its paramagnetic behaviour.
13. Explain the structure of ethene using sp2-hybridization.
14. Give four postulates of VSEPR theory.
15. Explain the geometry of NH3 using hybridization.
16. Define and explain Hess’s law of constant heat summation with examples.
17. Explain bomb calorimeter for the measurement of enthalpy of a reaction.
18. Explain the first law of thermodynamics.
19. Describe the electrolysis of molten sodium chloride and a concentrated solution of
sodium chloride. (OR) Write four industrial applications of electrolysis.
20. Define electrochemical series. Write its three applications in detail.
21. Discuss measurement of electrode potential of zinc by SHE?
22. Chapter no.8 numerical no. 24,25,23(a). Example no. 4,5,7.
23. Chapter no.3 numerical no. 18,19,20. Example no.5,3,6,7.