ch7 mole concept and stoichiometry

Question 1

[f] how to get no. of particles

Answer 1

no of particles = no. of moles x 6.02 x 10^23

Question 2

[f] how to get mass (g)

Answer 2

mass (g) = no. of moles x molar mass (g/mol)

Question 3

[f] how to get volume of gas (rtp)

Answer 3

vol of gas at rtp = no. of moles x 24dm^3

Question 4

[f] concentration in mol/dm3

Answer 4

conc in mol/dm3 = no of moles/volume (dm3)
- only applies to aqueous state sltn

Question 5

[f] concentration in g/dm3

Answer 5

conc in g/dm3 = mass/volume (dm3)
- only applies to aqueous state sltn

Question 6

[f] convert b/w mol/dm3 and g/dm3

Answer 6

conc (g/dm3) = (conc in mol/dm3)(molar mass)

Question 7

steps to find empirical formula

Answer 7

1) Ar of each element
2) no of moles of each element present
3) mole ratio of each element (no. of mol/lowest of that)
4) simplify mole ratios

Question 8

steps to find molecular formula from empirical formula

Answer 8

1) find multiple, n = (Mr of compound)/(Mr of empirical formula)
2) yuh

Question 9

[stoichiometry] calculations involving masses

Answer 9

1) find no of moles of reactant/product given
2) find no of moles of the other reactant/product using mole ratio/volume ratio
3) calc mas of substance from no of moles