Answer:
CH2N2
Explanation:
To find the molecular formula, we must first find the empirical formula as follows:
28.57% C - 28.57g of Carbon
4.80% H - 4.80g of Hydrogen
66.64% N - 66.64g of Nitrogen
Next, we convert this mass values to mole by dividing by their respective atomic mass.
C = 28.57/12 = 2.38mol
H = 4.80/1 = 4.80mol
N = 66.64/14 = 4.76mol
Next, we divide each mole value by the smallest mole value (2.38mol)
C = 2.38mol ÷ 2.38 = 1
H = 4.80mol ÷ 2.38 = 2.01
N = 4.76mol ÷ 2.38 = 2
The empirical ratio of C, H and N is therefore 1:2:2. Hence, the empirical formula is CH2N2
To calculate the molecular formula;
(CH2N2)n = 42.04 g/mol
{12 + 1(2) + 14(2)}n = 42.04
{12 + 2 + 28}n = 42.04
{42}n = 42.04
n = 42.04/42
n = 1.00009
Since n = 1, molecular formula is CH2N2