Rates of Reaction

Question 1

What are the 5 factors affect the rate of reaction? (5)

Answer 1

1. Increase concentration
2. Increase surface area
3. Increase pressure
4. Increase temperature
5. Adding catalysts

Question 2

What happens in a chemical reaction?

Answer 2

The recant is broken down, then build up to form the product:

AB + C —> AC + B

Question 3

Increased the temperature produces 1 effects? (1)

Answer 3

Increased energy meaning the particles collied more frequently

Question 4

Increasing concentration increases the reaction rate because…..? (1)

Answer 4

There are more particles in the same volume meaning they are more likely to collied more frequently

Question 5

Increasing gas pressure increases the reaction rate because…..?

Answer 5

There is less space for the particles to move around freely meaning they will now collied more frequently

Question 6

Increasing the surface area increases the reaction rate because…..?

Answer 6

There are more places for the coalitions to happen so more frequent coalitions occurring

Question 7

Using a table how do you calculate the rate of reaction? (Quantity of product produced)

Answer 7

Quantity of reactant used/Time (sec)

Question 8

Using a table how do you calculate the rate of reaction? (Quantity of reactant used)

Answer 8

Quantity of product made/Time (sec)

Question 9

Using a graph how do you calculate the rate of reaction? (with a straight line of best fit)

Answer 9

Gradient = rate of reaction

Gradient = y1 - y2

                -----------

                 x1 - x2

Question 10

How does a catalyst work?

Answer 10

A catalyst works by providing an alternative pathway with lower activation energy

Question 11

What is the definition of reaction rate?

Answer 11

The speed at which a chemical is used up or produced

Question 12

What is the definition of kinetic theory?

Answer 12

The greater the temperature, the greater the kinetic energy of particles, the faster the particles move

Question 13

What is the definition of activation energy?

Answer 13

This is the minimum collision energy required for two particles to react

Question 14

What is the definition of catalyst?

Answer 14

A catalyst is a substance that speeds up the rate of reaction but is chemically unchanged at the end of the reaction

Question 15

Describe the experiment to investigate SA? (4)

Answer 15

1. Half fill 2 test tubes with 1M of hydrochloric acid
2. Add a 2cm strip of magnesium ribbon to one test tube
3. Add half a spatula of magnesium powder to the other test tube
4. Write down your observations

Question 16

Describe the experiment to investigate Temp? (5)

Answer 16

1. Half fill 2 test tubes with 1M of hydrochloric acid
2. Place one of the test tubes in a hot water bath
3. After two minutes add a to 2cm strip of magnesium ribbon to each test tube
4. After you put the 2CM of magnesium ribbon in the test-tube start a stopwatch and record until the magnesium ribbon has disappeared
5. Write down your observations

Question 17

Describe the experiment to investigate concentration? (4)

Answer 17

1. Half fill 1 test tubes with 1M of hydrochloric acid
2. Half fill another test tube with 0.1 M of hydrochloric acid
3. Add a to 2cm strip of magnesium ribbon to each test tube
4. Write down your observations

Question 18

Describe the experiment to investigate SA using marble chips?

Answer 18

1. Obtain 4 large marble chips(CaCO3) of approximately the same size
2. Measure 25cm^3 of 1 mol dm^-3 of hydrochloric acid using a measuring cylinder and pour it into a small conical flask with a gas syringe attachment
3. Places the first 2 marble chips into the acid in the conical flask and record the volume of carbon dioxide at 20 sec intervals for 240 sec
4. Using the other 2 pieces of marble chips crush them into small pieces using a pestle and mortar.
5. Record your results in a table

Question 19

In the SA marble chip experiment which produced more CO2 over 240 sec? And why?

Answer 19

Powder, Because it has a larger surface area which means there’s more room for the particles to collide with so collisions are more frequent and more faster

Question 20

Describe the experiment to investigate catalysts? (3)

Answer 20

1. Using a measuring cylinder put 5cm^3 of hydrogen peroxide into six boiling tubes
2. The first is a control. Add 1/4 of a spatula of copper oxide to the second, a 1/4 of magnesium dioxide to the third, 1/2 a spatula of magnesium dioxide to the fourth, 1 piece of potato to the fifth, and 1 piece of liver to the sixth
3. Record your results and observations in the following table

Question 21

Increased the catalyst produces 1 effects? (1)

Answer 21

Increase the rate of reaction even further as it lowers the activation energy so particles can have more successful collisions

Question 22

Is a catalyst all used up in a reaction? Explain your answer?

Answer 22

No, as a catalyst isn’t a reactant in the chemical reaction it speeds up

Question 23

How can you prove a catalyst is not used up in a reaction?

Answer 23

The mass of the catalyst at the end of the reaction will be the same as the mass of the catalyst at the start.

Question 24

Describe the experiment to investigate catalyst and activation energy?

Answer 24

1. Set up the apparatus for the collection of oxygen gas in a field 250cm^3 measuring cylinder inverted in a bowl of water
2. Using a small measuring cylinder add 30cm^3 of hydrogen peroxide to a side-armed flask and then add 30cm^3of water
3. Use an electric balance to weigh out the mass of approximately 0.25 manganese dioxide catalyst
4. Add the manganese the oxide to the flask, then start the stopwatch
5. Collect the oxygen produced in the 250cm^3 measuring cylinder and record the volume of gas every 30 seconds
6. Continue recording until the reaction is stopped or the measuring cylinders fill
7. If the reaction stops record the final volume reached on the time taken

Question 25

If time increases during the catalyst and activation energy experiment what happens to the volume of oxygen?

Answer 25

The volume of oxygen will increase at a even pace

Question 26

At the end of the experiment what will the graph look like? (catalyst and activation energy)

Answer 26

Line will flatten or be horizontal as reaction has finished