Question

N has a mass of 26.19 H has a mass of 8.39 g and Cl has a mass of 65.42. Find the emperical formula?

Answer 1

You must divide every mass of each element for its molecular weight: N (26,19/14,007= 1,87), H (8,39/1,008=8,32, but maybe they where 7,39 g so you obtain 7,39/1,008=7,33) , Cl (65,42/35,45 =1,84). Now you divide by 4 the rate of H 7,33/4 = 1,83 and you obtain about the same number. This means that the empirical formula of the compound is NH4Cl (ammonium chloride)

Answer 2

The empirical formula is `"N"_2"H"_9"Cl"_2"`

Make sure the masses of all the elements add up to 100 g.

`"26.19 g + 8.39 g + 65.42 g = 100 g"`

Determine moles of each element using the molar mass.

`"26.19 g N"` x `"1 mol N"/"14.0067 g N"` = `"1.870 mol N"`

`"8.39 g H"` x `"1 mol H"/"1.00794 g H"` = `"8.32 mol H"`

`"65.42 g Cl"` x `"1 mol Cl"/"35.453 g Cl"` = 1.845 mol Cl"#

Determine mole ratios by dividing the moles for each element by the lowest number of moles.

N: `"1.870 mol"/"1.845 mol"` = `"1.014"`

H: `"8.32 mol"/"1.854 mol"` = `"4.51"`

Cl: `"1.854 mol"/"1.854 mol"` = `"1.000"`

Multiply the mole ratios times 2 in order to make the mole ratio for oxygen a whole number..

Empirical formula is `"N"_2"H"_9"Cl"_2"`