Getting the most from reactants

Question 1

What does the UK chemical industry make a major contribution to?

Answer 1

the quality of life in the country

Question 2

Give 4 examples of products which are made on a huge scale on a daily basis?

Answer 2

medicines
plastics
paints
cosmetics

Question 3

What are industrial processes designed to do?

Answer 3

maximise profit and minimise the impact on the environment

Question 4

Give 5 examples of factors influencing process design ?

Answer 4

availability, sustainability and cost of feedstock(s)
opportunities for recycling
energy requirements
marketability of by-products
product yield

Question 5

Give 3 examples of environmental considerations?

Answer 5

minimising waste
avoiding the use or production of toxic substances
designing products which will biodegrade if appropriate

Question 6

What is the research and development stage?

Answer 6

initial stage of planning

Question 7

What is the laboratory process stage?

Answer 7

Initial trial using small quantities

Question 8

What is the pilot study stage?

Answer 8

Trial using larger quantities in a bigger reactor to understand engineering aspects of the process.

Question 9

What is the production stage?

Answer 9

Production is carried out in a factory/plant on a huge scale, producing tonnes of products

Question 10

What is the process and review stage?

Answer 10

The process is reviewed and optimised to have the best conditions and best yield. A marketing team will sell the product.

Question 11

What is a feedstock?

Answer 11

a reactant from which other chemicals can be extracted or synthesised.

Question 12

What are feedstocks derived from?

Answer 12

raw materials

Question 13

What are raw materials?

Answer 13

substances that can be used directly in their original form without being treated.

Question 14

What are the 5 main raw materials used in the chemical industry?

Answer 14

fossil fuels
metallic ores and minerals
air 
water
organic materials such as oil and starch

Question 15

What would make feedstock profit making?

Answer 15

local feedstock
feedstock that is in abundance
low cost of feedstock

Question 16

When would feedstock cause a profit loss?

Answer 16

feedstock has to be transported for far away
feedstock may become scarce
feedstock is too expensive.

Question 17

When would opportunities for recycling cause a profit to be made?

Answer 17

if unreacted materials can be fed back into the process this will improve efficiency and profitability.

Question 18

When would opportunities for recycling cause a profit to be loss?

Answer 18

if it is difficult to separate materials at the end of the reaction, this makes it inefficient and wasteful.

Question 19

When would energy requirements cause a profit to be made?

Answer 19

exothermic reactions can be used to sustain the heat in a reaction.
catalysts can lower the energy required for the reaction

Question 20

When would energy requirement cause a profit to be lost?

Answer 20

reactions which require a lot of heating and cooling require energy.

Question 21

When would marketability of by-products cause a profit to be made?

Answer 21

some by-product can be sold for use in other areas of the chemical industry.

Question 22

When would marketability of by-products cause a profit to be loss?

Answer 22

if by-products are toxic or corrosive they will be expensive to deal with and may harm the environment.

Question 23

When would product yield cause a profit to be made?

Answer 23

high yields are very profitable

Question 24

When would product yield cause a profit to be loss?

Answer 24

low yields cost time and money

Question 25

What is also important to consider in an industrial process?

Answer 25

thedesign of the chemical plant to ensure it has good infrastructure,i.e. good transport links (road and sea for export and import of materials) and safety precautions

Question 26

What can a flow diagram be used for?

Answer 26

by engineers and industrial chemists when designing a process. It allows them to consider important aspects of the whole chemical process.

Question 27

In most chemical reactions what happens to one reactant ?

Answer 27

Gets used up before the other

Question 28

What happens to the reaction of one reactant is used up?

Answer 28

It stops

Question 29

What is the reactant left over said to be?

Answer 29

In excess

Question 30

What is the reactant not in excess called?

Answer 30

Limiting reactant

Question 31

What does the limiting reactant determine ?

Answer 31

The quantity of product made

Question 32

What is the molar volume of a gas?

Answer 32

The volume occupied by 1 mole of a gas at a stated room temperature and pressure

Question 33

What is the approximate molar volume of gas at room temperature (20•c) and 1 atmospheres pressure?

Answer 33

22.4 litres

Question 34

What is the same for all gases?

Answer 34

22.4 litres at room temperature and 1 atmospheres pressure

Question 35

Many reactions do not go to completion. What does this mean?

Answer 35

The quantity of product obtained from the reaction (actual yield) is less than the calculated (theoretical yield)

Question 36

Why would there be a lower actual yield than theoretical yield?

Answer 36

May be due to products being lost or the reaction being reversible

Question 37

What is the equation for percentage yield?

Answer 37

Actual yield / theoretical yield x100

Question 38

What is the equation to find the actual yield?

Answer 38

Theoretical yield x %yield/ 100

Question 39

What does atom economy measure?

Answer 39

The proportion of the total mass of all starting materials converted into the desired products

Question 40

If by-products were produced what would the atom economy most likely be and why?

Answer 40

Low as there will not be a high proportion of the desired products

Question 41

What is the equation for atom economy?

Answer 41

Mass of desired product(s)/ total mass of reactant(s) x100