Unit 3 - Getting the most from reactants

Question 1

What is a feedstock

Answer 1

A chemical other chemicals can be extracted or synthesised from

Question 2

What is a raw material

Answer 2

A substance found naturally in the earths crust or atmosphere

Question 3

What is the formula for number of moles when given molar volume

Answer 3

n = V/Mv

Question 4

When is water included in gas volumes equations

Answer 4

When stated as gaseous or temperature above 100°C

Question 5

What happens when NaOH is added to a gas volume mixture containing CO₂ in a gas mixture question

Answer 5

CO₂ must be removed from gas mixture

Question 6

What’s the higher method for basic mass or volume calculations

Answer 6

• Theoretical ratio
• Calculate moles for given value(s)
• Apply moles found to ratio
• Calculate what is asked in question

Question 7

What is the value for molar volume

Answer 7

22.4 litre mol^-1

Question 8

What are the steps for gas volume questions

Answer 8

• Write volume ratio for all necessary
• Find limiting reactant (completely used up)
• Find left over gas accordingly

Question 9

What are the steps for percentage yield questions

Answer 9

• Find theoretical mass produced
• Use actual value given
• Apply to formula

Question 10

What are the steps for atom economy questions

Answer 10

• Find GFMs for all reactants
• Find GFMs for product(s)
• Apply to formula (REMEMBER BIG NUMBERS)

or

1. Find mass of all reactants. (Use number of moles from equation)
2. Find mass of desired product. (Use number of moles from equation)
3. Use AE = mass of desired product/mass of reactants x100

Question 11

What are the steps for limiting/ excess reactants

Answer 11

• Find moles for chemicals asked
• THEORY HAVE NEED