physical chemistry

Question 1

what is the rate of a chemical reaction

Answer 1

how fast the reactants are changed into products

Question 2

what is the collision therory

Answer 2

-the more collisions there are the faster the reaction is
-particles have to collide with enough energy for the collision to be successful

Question 3

what is the minimum amount of energy particles need to react known as

Answer 3

activation energy

Question 4

what are the 4 factors that affect the rate of reaction

Answer 4

-temperature
-concentration of a solution/pressure of a gas
-surface area
-a catalyst

Question 5

how does increasing the temperature affect the rate of a reaction

Answer 5

-when temp. is increased, particles move quicker
-so there are more frequent collisions
-increasing the rate of reaction

Question 6

how does increasing the concentration of a solution increase the rate of a reaction

Answer 6

-the higher the concentration, the more particles in the same volume
-makes collisions more likely, so rate of reaction increases

Question 7

how does increasing the pressure of a gas increase the rate of reaction

Answer 7

-more pressure means the particles are more crowded
-so the frequency of collisions will increase
-rate of reaction increases

Question 8

how does a larger surface area lead to a higher rate of reaction

Answer 8

-particles will have more area to work on, so frequency of collisions will increase
-reaction is faster with a larger surface area to volume ratio

Question 9

how does a catalyst affect the rate of a reaction

Answer 9

-decreases the activation energy
-by providing a different reaction pathway with a lower activation energy
-so more of the particles have at least the minimum amount of energy needed for a reaction to occur

Question 10

what are the ways rate of reaction can be measured

Answer 10

-precipitation
-change in mass
-volume of gas given off