Reaction kinetics

The rate of a reaction usually increases with temperature because:

• 1 Molecules get larger
• 2 More molecules have enough energy to react
• 3 Activation energy increases
• 4 Pressure falls

A catalyst increases rate by:

• 1 Lowering the activation energy
• 2 Raising Kc
• 3 Raising temperature
• 4 Increasing concentration

For rate = k [A]^2, doubling [A] changes the rate by a factor of:

• 1 2
• 2 8
• 3 4
• 4 1

The unit of rate of reaction is:

• 1 s-1 only
• 2 mol dm-3
• 3 dm3 mol-1
• 4 mol dm-3 s-1

The half life of a first order reaction is:

• 1 Independent of initial concentration
• 2 Proportional to concentration
• 3 Inversely proportional to k only
• 4 Zero

The order of a reaction is found:

• 1 From the colour
• 2 From the name
• 3 From the equation only
• 4 By experiment

A reaction rate typically doubles for a 10 degree rise in temperature. This is a rule of thumb that shows:

• 1 Rate rises with temperature
• 2 Temperature has no effect
• 3 The reaction stops
• 4 Rate falls with temperature

A heterogeneous catalyst is:

• 1 In a different phase from the reactants
• 2 In the same phase
• 3 A liquid always
• 4 A gas always