(3) quantitative chemistry

Question 1

how do you calculate the number of moles

Answer 1

no. of moles = mass ÷ Mr

Question 2

what is a limiting reagent

Answer 2

a reactant that gets completely used up in a reaction before the rest, forcing the reaction to stop

Question 3

how do you find the volume of a gas at room temperature

Answer 3

volume = (mass ÷ Mr) x 24

Question 4

one mole of any gas occupies __dm^3

Answer 4

3

24dm

Question 5

how do you calculate concentration

Answer 5

concentration (g/dm^3) = mass of solute ÷ volume of solvent

concentration (mol/dm^3) = no. of moles of solute ÷ volume of solvent

Question 6

what is atom economy

Answer 6

atom economy is the percentage of reactants forming useful products

Question 7

how do you calculate atom economy

Answer 7

atom economy = (Mr of desired products ÷ Mr of all reactants) x100

Question 8

how do you find percentage yield

Answer 8

% yield = (mass actually made ÷ maximum theoretical mass) x 100