Skip to content
p.paperbanao.
Continue

Punjab (PTB) · Quarter book test · Free

1st Year Chemistry 2nd Quarter Book Paper

40 marks · 1 hour · 28 questions. Covers: 4 chapters (CHAP 5: States and Phases Of Mater to CHAP 8: Chemical Equilibrium).

Your school name

1st Year Chemistry 2nd Quarter Book Paper

1st Year · Chemistry · Punjab (PTB)

Name: ____________Roll No: ________Class/Section: ________Date: ________Total marks: 40Time: 1 hour

Q1. Multiple choice questions (Attempt all · 12 × 1 = 12)

  1. The order of reaction is:

    1. The total number of molecules taking part in the rate determining step

    2. The total number of molecules taking part in a chemical reaction

    3. Both a and b

    4. None of these

  2. Which type of equilibrium involves a change of state?

    1. Chemical

    2. Physical

    3. Ionic

    4. Molecular

  3. An energy profile shows a very flat region after the first peak before rising to a second, higher peak; what does this suggest about the intermediate?

    1. It is highly reactive.

    2. It is consumed quickly.

    3. It is relatively stable.

    4. It has a high activation energy for the next step.

  4. If absolute temperature of a gas is double and the pressure is reduced to one half, the volume of the gas will:

    1. Remain unchanged

    2. Increase four times

    3. Reduce to

    4.  Be doubled

  5. At the beginning the decrease in the concentration of reactants is:

    1. Slow

    2. Moderate

    3. Rapid

    4. None of these

  6. Which statement is true about a reversible reaction at equilibrium?

    1. All reactants are converted into products

    2. Microscopic changes stop

    3. The concentrations of products and reactants remain constant

    4. The reaction becomes irreversible

  7. Which of the following factors would lead to a greater enthalpy change of hydration(more exothermic)?

    1. A larger ionic radius and a smaller charge

    2. A smaller ionic radius and a smaller charge

    3. A larger ionic radius and a larger charge

    4. A smaller ionic radius and a larger charge

  8. Which one of the following have lowest vapour pressure at 25oC?

    1. Water

    2. Ethyl alcohol

    3. Acetone

    4. Diethyl ether

  9. The measurement of rate of reaction involving change in ionic concentration is followed by:

    1. Spectrometric method

    2. Chemical method

    3. Refractrometric method

    4. Conductivity method

  10. Kc = 0.040 at 450oC for the given reaction, evaluate Kp for the reaction.

    1. 0.40

    2. 0.64

    3. 2.4

    4. 0.052

  11. If the calorie content of a food is given as 500 Calories, what does this value fundamentally represent in terms of energy change?

    1. The maximum work the body can derive from that food.

    2. The total heat released when food is completely metabolized.

    3. The change in internal energy of the food during digestion.

    4. The activation energy required to break down the food molecules.

  12. When the external pressure is 23.7 torr, boiling point of water is:

    1. 25 oC

    2. 100 oC

    3. 98 oC

    4. 200oC

Q2. Short questions (Attempt any 8 of 12 · 8 × 2 = 16)

  1. Explain why bond breaking is always an endothermic process, while bond formation is always exothermic, in the context of r.

  2. Why does changing the concentration of a substance not alter the value of the equilibrium constant?

  3. What is meant by order of reaction?

  4. How do you differentiate between crystalline solids and amorphous solids?

  5. If a reaction involves a phase change in one of the reactants or products, how must bond energy calculations be adjusted to provide a more accurate ?

  6. The change of volume disturbs the equilibrium position for some of the gas phase reactions but not the equilibrium constant.

  7. A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration is doubled and reduced to half?

  8. Why does wind increase the rate of evaporation of a liquid?

  9. Can an energy profile diagram definitively prove the exact molecular mechanism of a reaction? Explain briefly.

  10. How can you experimentally determine if a system is at equilibrium?

  11. Rate of reaction changes with time. Why?

  12. London dispersion forces are weaker than dipole-dipole forces. Why?

Q3. Long questions (Attempt any 3 of 4 · 3 × 4 = 12)

  1. In a laboratory experiment,150 cm3 of a volatile liquid was completely vaporized at 98 oC and a pressure of 1.01 x 105 pa.The mass of the vapor was found to be 0.495 g.Determine the molecular mass of the liquid (R=8.314 JK-1 mol-1).

  2. Write down the Kc for the following reactions. Suppose that the reaction mixture in all the case is ‘V’ dm-3 (i) CH3COOH + CH3CH2OH (eq) CH3COOC2H5 + H2O (ii) 2HI (eq) H2 + I2 (iii) N2 + 3H2 2NH3

  3. Three experiments that have identical conditions were performed to measure the initial rate of the reaction.

    Experiment [HI] (M) Rate (M/s)
    1 0.015 1.1x10-3
    2 0.030 4.4x10-3
    3 0.045 4.4x10-3

    Write the rate law for the reaction. Find the value and units of the specific rate constant, k.

  4. What is the standard enthaply change? Give different types of enthaply changes with their examples.