What is the empirical formula of a substance with 74.0% C , 8.65% H, and 17.4% N?

1 Answer
Jun 25, 2016

Answer:

#C_5H_7N#

Explanation:

First, assume that there is 100 g of substance.

Next is to calculate the number of moles or each element:

#74.0 g C * (1mol C )/ (12.01 g) ~~ 6.16 mol C#
#8.65 g H * (1mol H )/ (1.008 g) ~~ 8.58 mol H#
#17.4 g N * (1mol N )/ (14.01 g) ~~ 1.24 mol N#

After getting the mol of each element, you can calculate now the mole ratio. Do this by dividing each number of moles by the lowest number of moles obtained.

# C= (6.16/1.24)~~ 5#
# H= (8.58/1.24)~~ 7#
# N= (1.24/1.24)~~ 1#

Therefore, the empirical formula of a substance with 74.0% C , 8.65% H, and 17.4% N is #C_5H_7N#