catalysts and rate of reactions

Question 1

what speeds up a chemical reaction

Answer 1

-temperature
-concentration
-a catalyst
-volume

Question 2

what speeds up reactions

Answer 2

-a catalyst
-metals eg.gold
-light
-temp
-conc
-volume
-pressure

Question 3

what is a catalyst?

Answer 3

increases the rate of a reaction
doesnt get used up
doesnt change the products in the reaction

only need a very small mass of catalyst is needed to increase the rate of a reaction. However, not all reactions have suitable catalysts.

Question 4

advantages of a catalyst

Answer 4

-doesnt get used up
-only need to use a small amount
-reusable
-speeds up the reaction

Question 5

disadvantages of a catalyst

Answer 5

-expensive
-not all reactions have a suitable catalyst
-can be poisoned

Question 6

how do catalysts work?

Answer 6

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

This does not change the frequency of collisions. However, it does increase the frequency of successful collisions because a greater proportion of collisions now exceeds this lower activation energy.

Question 7

name a catalyst

Answer 7

-enzymes which break down food in the digestive system for eg amalayse

Question 8

what is rate of reaction?

Answer 8

a measure of how quickly a reactant is used up, or a product is formed.

Question 9

what is the collision theory?

Answer 9

For a chemical reaction to happen,

-reactant particles must collide with each other

-the particles must have enough energy for them to react.

Question 10

how does temp affect rate of reaction?

Answer 10

if the temperature is increased

-reactant particles move more quickly.

-they have more energy. the particles collide successfully more often.