Stoichiometry

Question 1

Determine the formula of an ionic compound from the charges on the ions present

Answer 1

ammonium: NH4 +
hydroxide: OH -
nitrate: NO3 -
sulfate: SO4 2-
carbonate: CO3 2-
hydrogencarbonate: HCO3 -

Question 2

Define the mole and the Avogadro constant

Answer 2

Mole: number of particles that is equal to the number of 12g of 12 C
Avagadro constant: the number of particles (6.023 x 10 to the power of 23) in one mole of a substance

Question 3

Moles eq (3)

Answer 3

number of moles = mass/ Ar or Mr
number of moles = V / 24000 cm3
number of moles = V/1000 x concentration

Question 4

Calculate % yield and % purity

Answer 4

% yield = actual yield/ predicted yield x100
% purity = mass of pure product/ mass of impure product x100
(pg62)