10th Class Chemistry First half Book Paper

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

1. Which of the following does not involve an electrolytic process?
   1. Refining of copper
   2. Manufacture of Sodium from NaCl
   3. Electroplating of steel
   4. Reduction of metal oxide by a reducing agent.
2. What does a small standard error (e.g., 0.1°C) show?
   1. That the value is uncertain
   2. That the average value is accurate
   3. That data is not useful
   4. That the experiment should be redone
3. One mole of $H_2O$ has a mass of:
   1. 10 g
   2. 18 g
   3. 16 g
   4. 23 g
4. Which of the following represents Avogadro’s law?
   1. V ∝ n
   2. V ∝ P
   3. V ∝ T
   4. PV = constant
5. Which of the following is NOT a factor affecting the rate of reaction according to collision theory?
   1. Number of particles per unit volume
   2. Activation energy
   3. Presence of a catalyst
   4. Molar mass of reactants
6. Which insoluble base reacts with H₂SO₄ to produce copper(II) sulphate?
   1. CaCO₃
   2. CuO
   3. NaOH
   4. Zn
7. The catalyst used in the Contact Process is:
   1. Iron oxide
   2. Vanadium pentoxide
   3. Nickel
   4. Platinum
8. The cathode always produces which gas in both dilute and concentrated halide solutions?
   1. Oxygen
   2. Hydrogen
   3. Chlorine
   4. None
9. What did the Phlogiston Theory try to explain?
   1. Atomic structure
   2. Radioactivity
   3. Burning (combustion) and rusting
   4. Energy level
10. A solution has a strength of 50 g/dm³. Expressed in g/cm³ it is:
    1. 0.05 g/cm³
    2. 0.5 g/cm³
    3. 5 g/cm³
    4. 0.005 g/cm³
11. Drug diffusion rate depends on:
    1. Volume of container only
    2. Pressure alone
    3. Concentration gradient
    4. Shape of drug molecules
12. Slowing down specific reactions in food products is achieved by:
    1. Adding acids
    2. Increasing transportation time
    3. Controlling temperature and humidity
    4. Using high pressure only