According to collision theory, for a reaction to occur, particles must:
A) Collide with energy less than the activation energy.
B) Collide with the correct orientation and sufficient energy.
C) Collide at low temperatures.
D) Collide only in the presence of a catalyst.
Increasing the concentration of reactants in a solution increases the reaction rate because:
A) Particles have higher kinetic energy.
B) There are more frequent collisions between particles.
C) The activation energy decreases.
D) The temperature automatically rises.
In the reaction between marble chips (CaCO₃) and HCl, powdered marble reacts faster than lumps because:
A) Powder has a lower activation energy.
B) Powder increases the surface area for collisions.
C) Lumps absorb heat more efficiently.
D) Powder reduces the need for a catalyst.
The diagram shows the pathways of a reaction, with and without a catalyst. Which letter represents the overall energy change for the reaction?
A
B
C
D
Which factors could help to explain this observation?
A. 1, 2 and 3 are correct
B. 1 and 2 are correct
C. 2 and 3 are correct
D. 1 only is correct
The diagram shows a Bolzmann distribution of molecular energies for gaseous mixture. The distrubtion has a peak labelld P on the diagram.
A. The height of the peak P decreases and the activation energy moves to the left.
B. The height of the peak P decreases and the activation energy moves to the right.
C. The height of the peak P decreases and the activation energy does not change.
D. The height of the peak P increses and the activation energy moves to the left.
Why does the addition of water decrease the rate of the reaction?
A. 1, 2 and 3 are correct
B. 1 and 2 are correct
C. 2 and 3 are correct
D. 1 only is correct
Which solid-line curve represents the distribution of molecular energies in a gas at 500 K if the dotted-line curve represents the same gas at 300 K?
A
B
C
D
The reaction E + F G + H is catalysed by platinum.
A. 1, 2 and 3 are correct
B. 1 and 2 are correct
C. 2 and 3 are correct
D. 1 only is correct
In the Haber process for manufacture of ammonia, why is the heterogeneous catalyst iron in a finely divided state?
A. to increase its surface area
B. to produce the maximum reduction in the activation energy
C. to reduce its loss during the reaction
D. to reduce its surface area
The temperature of a sample of an inert gas is increased. What effect does this have on the number of molecules with most probable energy and with high energy?
A
B
C
D
For the reaction N2(g)+3H2(g) ⇌ 2NH3(g) , which change will increase both the equilibrium yield of NH3 and the reaction rate?
A) Adding an inert gas at constant volume
B) Increasing the temperature
C) Decrasing the total volume
D) Adding a catalyst
What is the correct title of Chapter 9?