6: Chemical kinetics

Question 1

what effect does a catalyst have on activation energy

Answer 1

A catalyst provides an alternative reaction pathway with a lower activation energy than the uncatalysed pathway.

Question 2

what effect does decreased temp have on Maxwell Boltzmann distribution curve

Answer 2

The peak of the curve shifts to the left and increases in height so that the same area under the curve is present, as the overall number of particles remains constant.

Question 3

As the molar mass of the gas increases, the average molecular speed decreases. All of these gases have the same amount of kinetic energy.

Answer 3

At the same temperature, all particles have the same amount of kinetic energy, but the speed of the particles will vary with mass. Gas particles with smaller masses will have a greater speed and particles with a larger mass will have a lower speed.

Question 4

When examining the effect of a factor on rate of reaction, the
_________
rate of reaction is used for comparison, rather than the average rate.

Answer 4

Initial; because As a reaction progresses, the rate of reaction
decreases so the initial rate of reaction is the most reliable for comparison