Making a reaction go faster-Part 2

Question 1

the molecules in a sample of gas have a wide range of

Answer 1

energies

Question 2

in order to estimate what fraction of collisions will have the required activation energy, we need to know the

Answer 2

energy distribution of the molecules

Question 3

Maxwell-Boltzmann distribution curves are used to show

Answer 3

the distribution of molecular energies

Question 4

the four important pints about Maxwell-Boltzmann curves are:

Answer 4

• neither curve is symmetrical
• both curves start at the origin and finish by approaching the x-axis asymptomatically
• the area under each curve is the same
• the peak of T2 is displaced to the right and is lower than that for the peak T1

Question 5

the area under the curve to the right of the activation energy line represents the

Answer 5

fraction of molecules that has enough energy for the collisions to be successful

Question 6

an increase in temperature increases:

so the rate of reaction increases because:

Answer 6

• the fraction of molecules that possesses the required activation energy
• the rate of reaction increases because the number of successful collisions per second increases

Question 7

at pressure 100kPa and temp. 298K, a single gas molecule might have between………….and……………collisions per second depending on its size

Answer 7

10,000,000,000 and 100,000,000,000 collisions per second

Question 8

in soltion, at low and medium concentration, solute molecules can be entirely surrounded by……………..which is called a ……………………….

Answer 8

solvent molecules, called a ‘solvent cage’

Question 9

sometimes, solute molecules can become trapped int e same………………so the more ………………..occur

Answer 9

same solvent cage, so more collisions occur

Question 10

the two stages for reactions in solution are:

Answer 10

• the molecules have to come together by a process of diffusion into the same solvent cage
• the molecules then react