How would you do this?

The empirical formula : C₁₀H₂₀O

Given

Combustion of menthol

Required

The empirical formula

Solution

Mass of CO₂ produced : 0.449 g

mass C = 12/44 x 0.449 = 0.122

Mass water produced : 0.1840 g

Mass H = 2.1/18 x 0.1840 = 0.02

Mass O in menthol :

=mass sample - (mass C+mass H)

= 0.1595 - (0.122+0.02)

= 0.0175

Mol ratio C : H : O in sample :

= 0.122/12 : 0.02/1 : 0.0175/16

= 0.01 : 0.02 : 0.001

= 10 : 20 : 1

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.