C6 - Rates Of Reaction - Needs Work

Question 1

What is a formulation

Answer 1

Mixture where components have specific purposes combined to make a useful product

Question 2

Give 2 things needed for a chemical reaction to take place

Answer 2

Collision in the correct orientation
Sufficient activation energy

Question 3

What is activation energy?

Answer 3

Minimum amount of energy needed for a chemical reaction to happen

Question 4

What is the rate of reaction

Answer 4

Time taken for reactants to be used up/formulation of products etc

Question 5

Give 4 things that affect rate of reaction

Answer 5

Temperature
Surface area
Catalysts
Concentration/pressure

Question 6

How does temperature affect rate of reaction?

Answer 6

Increasing temperature gives particles more kinetic energy
Increases frequency of successful collisions
Rate of reaction increases

Question 7

How does increasing surface area increase rate of reaction

Answer 7

Leads to more particles exposed
Increases frequency of successful collisions
Rate of reaction increases

Question 8

How do catalysts increase rate of reaction

Answer 8

Provide a different pathway for the reaction to take place with a lower activation energy
Increase rate of reaction

Question 9

How does increasing concentration/pressure increase rate of reaction

Answer 9

More particles in a specific volume
Increases frequency of successful collisions
Rate of reaction increases

Question 10

Never write fractional answers when drawing tangents - only decimals

Question 11

What is a reversible reaction

Answer 11

A reaction where there is a forward and backward reaction taking place at the same time

Question 12

In a reversible reaction, one reaction is __ and the other is ____

Answer 12

Exothermic
Endothermic

Question 13

What is dynamic equilibrium?

Answer 13

Rate of forward and backwards reactions are equal
So concentrations of reactants and products are constant (NOT AMOUNTS)

Question 14

What type of system does dynamic equilibrium take place in?

Answer 14

A closed system

Question 15

How can you create a closed system in an experiment

Answer 15

Lids on beakers

Question 16

If temperature is increased which side (exo or endo) does equilibrium shift to (in an exam say left or right)?

Answer 16

Endothermic

Question 17

Why does equilibrium shift to the endothermic side if temperature is increased

Answer 17

Rate of endothermic reaction increases - to counteract the effect of rising temperature I think?

Question 18

Where does equilibrium shift to if pressure is increased?

Answer 18

To the side with the least moles
Yield on the side with the least moles increases (presumably the rate of the reaction towards this side increases therefore?)

Question 19

What does the haber process do?

Answer 19

Method for the industrial production of ammonia

Question 20

What is the forward reaction in the haber process

Answer 20

Exothermic

Question 21

What is the reaction for the haber process

Answer 21

(g)N2 + 3H2(g) <=> 2NH3(g)

Question 22

Give 2 ways the rate of reaction is I ncreased

Answer 22

Iron catalyst
High temperature

Question 23

Why is temperature decreased

Answer 23

To increase Exothermic (forward) direction yield - increase ammonia yield

Question 24

Why is pressure increased

Answer 24

Increase yield on the side with fewer moles (ammonia side)

Question 25

What pressure is the haber process done at?

Answer 25

200 atmospheres

Question 26

What temperature is teh haber process done at

Answer 26

450 degrees

Question 27

Remaining hydrogen and nitrogen from the haber process is ___

Answer 27

Recycled

Question 28

On cooling, ___ ammonia is removed

Answer 28

Liquid

Question 29

Give the method for measuring rate of reaction by measuring volume of gas produced

Answer 29

1. Measure 50 ml of HCl into a conical flask using a measuring cylinder 2. Add a 1g strip of magnesium into the conical flask 3. Start the stopwatch and record volume of gas release using a gas syringe every 10 seconds for 1 minute 4. Ploy results on a graph of product formed over time and find the gradient to calculate rate of reaction R. Repeat with different acid concentrations

Question 30

Give a method for finding rate of reaction by checking for colour change

Answer 30

1. Measure 50 ml of sodium thiosulfate solution into a conical flask with a measuring cylinder 2. Place the conical flask on top of a printed black cross 3. Measure 20ml HCl Ito a test tube and heat to 40 degrees with a water bath 4. Add teh HCl, swirl and start the timer 5. Time how long it takes for the cross to disappear by looking from above 6. Repeat for other temperatures of HCl 7. Plot a graph of temperature of reactants and rate of reaction (how long it took)

Question 31

What was the traditional fertiliser

Answer 31

Manure

Question 32

Give 3 things used in NPK fertilisers

Answer 32

Nitrogen Phosphorus Potassium

Question 33

Give 3 ways NPK fertilisers benefit food production

Answer 33

Growing tastier and bigger and enhances productivity

Question 34

How is nitrogen made

Answer 34

Made from ammonia from haber process

Question 35

Give stages of forming ammonium nitrate

Answer 35

Haber process Ammonia formed Ammonia used to make nitric acid React nitric acid with more ammonia to make ammonium nitrate fertiliser

Question 36

Give a way ammonium nitrate is formed

Answer 36

Ammonia from haber process reacted with sulfuric acid

Question 37

How is phosphorus obtained

Answer 37

From mined phosphate rock

Question 38

Why can’t phosphate rock be used as a fertiliser?

Answer 38

Its insoluble

Question 39

How is phosphorus made into a fertiliser?

Answer 39

Treated with nitric acid/Sulfuric acid to make a soluble salt for fertiliser

Question 40

In what two forms is mined potassium found in

Answer 40

KCl or K2SO4

Question 41

If energy change is positive in the forward direction, this reaction is endo/Exothermic?

Answer 41

Endothermic

Question 42

what is rate of reaction measured in

Answer 42

g/s or cm cubed/s or mol/s

Question 43

give 4 things affecting rate of reaction

Answer 43

pressure of reacting gases surface area of solid reactants temperature presence of catalysts