Rates Of Reaction

Question 1

What is the rate of reaction?

Answer 1

How fast the reactants in a chemical reaction are changed into products

Question 2

What is the collision theory?

Answer 2

The rate of a chemical reaction depends on:
•the collision frequency of reacting particles (the more collisions the faster the reaction is)
•the energy transferred during a collision (particles have to collide with enough energy to for the collision to be successful)

Question 3

What 4 factors affect the rate of reaction

Answer 3

1)Temperature
2)The concentration of a solution/ pressure of gas
3)surface area
4)the presence of a catalyst

Question 4

How does temperature increase the rate?

Answer 4

1)when the temperature is increased the particles and move faster
2)this leads to more frequent collisions
3)the faster they move the more energy they have so more of the collisions will have enough energy to make the reaction happen

Question 5

How does concentration increase the rate?

Answer 5

•if a solution is made more concentrated it means there are more particles knocking about in the same volume of water or in any other solvent
•when the pressure of gas is increased it means the same number of particles occupy a smaller space
•this leads to more frequent collisions

Question 6

How does surface area increase the rate ?

Answer 6

1)if one of the reactants is solid then breaking it up into smaller pieces will increase its surface area to volume ratio
2) this means that for the same volume of the solid the particles will have more area to work on
3) this leads to more frequent collisions

Question 7

How does using a catalyst increase the rate?

Answer 7

1) A catalyst is a substance that speeds up a reaction without being used up in the reaction itself
3)They work by decreasing the activation energy needed for the reaction to occur by providing an alternative reaction pathway with lower activation energy

Question 8

what would a quick reaction line look like on a graph?

Answer 8

-if the graph shows the volume of product agaisnt time it would have a steep line and become flat in a short time
-if the graph shows the mass of reactants against time the line would fall rapidly but slow as the reaction progresses