Limiting reagent and atom economy

Question 1

What does the term limiting reagent mean?

Answer 1

Reactant is not in excess, all moles of it will react
Reactant that finishes first

Question 2

What method must we must when calculating limiting reagent?

Answer 2

ICE !!
I - initial moles
C - change
E - end moles

Question 3

What is the atom economy of a chemical reaction?

Answer 3

A measure of how well atoms have been utilised

Question 4

What is the definition of atom economy?

Answer 4

A measure of how much waste product a reaction produces

Question 5

How do you calculate atom economy?

Answer 5

% atom economy = (Mr of desired product / Mr of total products) x 100

Question 6

How does atom economy help with sustainability?

Answer 6

Modern sustainability requires industries to operate processes with high atom economies and fewer pollutants.
Fewer fossil fuels = lower CO2 emissions.
Leads to a reduction in global warming.

Question 7

What type of atom economy do addition reactions have?

Answer 7

100% - only desired compound is formed
No by products - so no wastage

Question 8

Is the % yield & % atom economy the same?

Answer 8

No
Reaction can have a high % yield but low atom economy
Efficiency of a process depends on both factors