10th Class Chemistry Chapter 5 Test05. Reaction Kinetics

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. 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
2. 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
3. When more reactant particles are present in a given volume:
   1. Reaction slows down
   2. Collisions increase and reaction is faster
   3. Activation energy increases
   4. Products remain unchanged
4. How does a catalyst increase the rate of reaction?
   1. By decreasing the number of particles per unit volume
   2. By increasing the activation energy
   3. By providing an alternate pathway with higher activation energy
   4. By providing an alternate pathway with lower activation energy
5. Powdered zinc reacts faster with HCl than zinc granules because:
   1. Powder has more exposed surface area
   2. Powder has less density
   3. Powder absorbs HCl faster
   4. Powder has lower activation energy
6. At equilibrium, the concentration vs time curve becomes:
   1. Steep
   2. Flat
   3. Oscillating
   4. Constantly decreasing
7. Which physical parameter is NOT typically affected by the rate of reaction?
   1. Change in mass
   2. Temperature
   3. Formation of gas
   4. Colour of the reactants
8. Enzymes speed up reactions in living organisms by:
   1. Consuming themselves
   2. Providing necessary orientation
   3. Destroying reactants
   4. Increasing activation energy
9. Activation energy can be imagined as:
   1. A valley
   2. A hill that reactants must climb
   3. A straight line
   4. A flat surface
10. A catalyst speeds up a chemical reaction by:
    1. Increasing temperature
    2. Lowering activation energy
    3. Increasing concentration of products
    4. Increasing bond energy