The molar mass of a compound is 92 g/mol. Analysis of a sample of the compound indicates that it contains 0.606g of N and 1.390g of O. Find its molecular formula.

N2O4

Explanation:

To obtain the molecular formula of the compound, first, let us calculate the empirical formula for the compound. This is illustrated below:

N = 0.606g

O = 1.390g

Next, we divide the above by their molar masses

N = 0.606/14 = 0.0432

O = 1.390/16 = 0.0869

Next, we divide by the smallest

N = 0.0432/0.0432 = 1

O = 0.0869/0.0432 = 2

The empirical formula is NO2

The molecular formula is given by:

[NO2]n = 92

[14 + (16x2) ]n = 92

[14 + 32]n = 92

46n = 92

Divide both side by the coefficient of n i. e 46

n = 92/46

n = 2

The molecular formula = [NO2]n = [NO2]2 = N2O4

N2O4

Explanation:

Empericial formula

N=0.606/14

N=0.043

O=1.390/16

O=0.087

Divide both N and O by the smallest number which is 0.043

N=1

O=2

(NO2) n=92

(14 + (16*2)) n=92

(14+32) n=92

46n=92

Divide both sides by 46

n=2

Substitute n=2 in (NO2) n

= (NO2) 2

=N2O4