Rate of Reaction

Question 1

How many different ways can rates of reactions be found?

Answer 1

3

Question 2

What are the ways you can measure the rate of reaction?

Answer 2

Measuring the amount of reactants used

Measuring the number of products formed

Measuring the amount of time it takes for a reaction mixture to become opaque or change colour

Question 3

How to measure the number of reactants used?

Answer 3

• If one of the products is a gas, measure the mass in grams (g)of of the reaction mixture before and after the reaction takes place and the time it takes for the reaction to happen
• the mass of the mixture will decrease
• The units for the rate of reaction may then be given as g/s

Question 4

How do you measure the number of products formed>

Answer 4

• if one of the products is a gas, measure the total volume of gas produced in cubic centimetres (cm^3) with a gas syringe and the time it takes for the reaction to happen.
• the units for the rate of reaction may then be given as cm^3/s

Question 5

how to measure the time for a reaction mixture to become opaque or change colour?

Answer 5

-Time how long it takes for the mixture to change colour

-Rate of reaction~~ 1
————————————-
time is taken for a solution to
change colour

Question 6

What is the collision theory?

Answer 6

collision theory is used to predict the rate of chemical reactions

Question 7

What state of matter does collision theory usually predict?

Answer 7

gases

Question 8

Chemical reactions only happen when…?

Answer 8

reacting particles collide with each other with sufficient energy.

Question 9

What is the minimum amount of energy required to cause a reaction called?

Answer 9

The activation energy

Question 10

How many important factors are there that affect the rate of reaction?

Answer 10

four

Question 11

What are the factors that affect the rate of reaction?

Answer 11

temperature, concentration, surface area and catalysts

Question 12

How do temperatures affect reaction rates?

Answer 12

in a hot reaction mixture, the particles move more quickly-they collide more often and with greater energy, so more collisions are successful.

Question 13

How do concentrations affect reaction rates?

Answer 13

At higher concentrations, the particles are crowded closer together-they collide more often, so there are more successful collisions.

-increasing the pressure of reacting gases also increases the frequency of collisions

Question 14

How does surface area affect the rate of reaction?

Answer 14

• small pieces of a solid reactant have a large surface area in relation to their volume.
• More particles are exposed and available for collisions, so there are more collisions and a faster reaction

Question 15

When talking about reaction rates on graphs what does it mean if the line is steep?

Answer 15

the steeper the line the faster the reaction

Question 16

What happens if one of the reactants is used up on a reaction rates graph?

Answer 16

the reaction stops,in other words the line becomes horizontal.