Question

What is the molecular formula of a compound given the molar mass of the compound is 34.04 gram and the empirical formula isNH?(A)NHB) N4H4N2H6N2H2

Answer 1

1) List the known and unknown quantities.

Molar mass: 34.04 g.

Empirical formula: NH.

Molecular formula: unknown.

2) Find the molar mass of the empirical formula.

N: 14.007 g/mol.

H: 1.008 g/mol.

N + H = 14.007 + 1.008 = 15.015 g/mol.

3) Divide the molar mass by the molar mass of the empirical formula

`X=(34.04)/(15.015)`
`X=2.27`

Multiply the subscripts of the empirical formula by 2.

`N_2H_2`

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