In depth Triple Chemistry (3c)

  • Created by: HarveyCB
  • Created on: 06-10-18 14:56
What is atom economy
The percentage of products that are useful
1 of 31
What does a higher atom economy mean
The process is greener
2 of 31
How do you calculate atom economy
Mr of desired products divided by Mr of all reactants x100
3 of 31
How can you find percentage waste
By subtracting the atom economy from 100
4 of 31
If a reaction has only one product, what is the atom economy
100%
5 of 31
What are the two types of advantage of atom economy
Economic and environmental
6 of 31
What are the economic advantages of high atom economy
Low atom economy reactions arent profitable, as they need more raw material to produce a certain amount of product, and they produce more waste. Waste is expensive to remove and dispose of responsibly, and raw materials are expensive
7 of 31
How can you overcome the problems of excess waste products
Find a use for them, so you have useful by products
8 of 31
What are the environmental advantages of high atoms economies
They use up fewer raw materials and produce less waste
9 of 31
Why are reactions with high atom economies more sustainable
They use up less finite resources, and damage as little of the environment as possible
10 of 31
What is percentage yield
A comparison between the theoretical yield and the actual yield of a reaction
11 of 31
What is the theoretical yield
The maximum amount of products you would get if all the reactants formed and no products were lost
12 of 31
What does a 100% percentage yield mean
You got all the expected products
13 of 31
What's does a 0% percentage yield mean
No products were made
14 of 31
How can you calculate percentage yield
Mass of product actually made divided by theoretical yield x100
15 of 31
What units should be used for the actual and theoretical yields
g
16 of 31
Why do we never get a 100% yield
Some product or reactant always gets lost along the way, whether its in school experiments or on an industrial scale
17 of 31
What are the three main reasons for not getting a 100% percentage yield
The reaction is reversible, product is lost when its separated from the reactants, or there may be unexpected reactions
18 of 31
What is a reversible reaction
A reaction where the products themselves can react to produce the original reaction
19 of 31
How does a reversible reaction affect percentage yield
If it is reversible, the reactants will never be fully converted to products, as some of the products are always reacting to change back to the original reactants
20 of 31
How is product lost when its removed from the reactants
When you filter a liquid to remove solids, you will always lose either some of the solid or liquid you want, as it will remain on the filter paper. Transference between containers also loses material, as its left on the surface of the old container
21 of 31
How do unexpected reactions affect percentage yield
The reactants may react with gases in the air, or impurities in the reaction mixture, forming more waste products
22 of 31
Why do industries have to choose which reactions to use carefully
To make sure the process is economical and sustainable
23 of 31
What are five factors that need to be considered when choosing an industrial reaction
Atom economy, yield, rate, equilibrium position, and usefulness of by products
24 of 31
Why do industries consider atom economy
A higher atom economy means less waste and raw materials, making it cheaper and more sustainable
25 of 31
Why do industries consider percentage yield
High percentage yield means less wasted reactants (cheaper), less waste and less raw materials (more sustainable)
26 of 31
Why do industries consider rate of reaction
Industrial reactions must occur relatively quickly to be useful
27 of 31
What is equilibrium position
The point where the rate of reaction is the same between reactants and products in a reversible reaction, so the amount of products and reactants stay the same
28 of 31
Why do industries consider equilibrium position
Being able to control the position of equilibrium to maximise the amount of product is important to make the industrial process profitable
29 of 31
Why do industries consider the usefulness of by products
If the by products are useful, that means less waste
30 of 31
Give an example of a industrial reaction with a useful by product
The production of nylon gives ammonium sulphate as a by product, which can by used as fertiliser
31 of 31

Other cards in this set

Card 2

Front

What does a higher atom economy mean

Back

The process is greener

Card 3

Front

How do you calculate atom economy

Back

Preview of the front of card 3

Card 4

Front

How can you find percentage waste

Back

Preview of the front of card 4

Card 5

Front

If a reaction has only one product, what is the atom economy

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all 3c- Atom economy and yield resources »