Question

An unknown compound contains only C , H , and O . Combustion of 5.80 g of this compound produced 14.2 g CO 2 and 5.80 g H 2 O . What is the empirical formula of the unknown compound

Answer 1

Empirical formula is C₄H₈O

Step-by-step explanation:

Empirical formula:

It is the simplest formula gives the ratio of atoms of different elements in small whole number

Given data:

Mass of compound = 5.80 g

Mass of CO₂ = 14.2 g

Mass of water = 5.80 g

Empirical formula = ?

Solution:

Percentage of H = 5.80 / 5.80× 2/18 ×100= 11%

Percentage of C = 14.2 /5.8 ×12/44 × 100= 67%

Percentage of O = 100 -( 67+11) = 22%

Number of gram atoms:

Number of gram atoms of H = 11 / 1 = 11

Number of gram atoms of O = 22 / 16 = 1.4

Number of gram atoms of C = 67 / 12 = 5.6

Atomic ratio:

C : H : O

5.6/1.4 : 11/1.4 : 1.4/1.4

4 : 8 : 1

C : H : O = 4 : 8 : 1

Empirical formula is C₄H₈O.