Question

Combustion of 1.000g of an organic compound that contains C, H and O produces 2.360g CO₂ and 0.640g H₂O. What is the empirical formula of the compound? Please show work

Answer 1

Solution:

1) mass of each element:

carbon ⇒ 2.360 g x (12.011 / 44.0098) = 0.644 g
hydrogen ⇒ 0.640 g x (2.016 / 18.015) = 0.071 g
oxygen ⇒ 1.000 minus (0.644+0.0711) = 0.285 g

Notice that there was oxygen in the compound and that the problem did not tell you that.

2) moles of each element:

carbon ⇒ 0.644 g / 12.011 g/mol = 0.054 mol
hydrogen ⇒ 0.0711 g / 1.0 g/mol = 0.071mol
oxygen ⇒ 0.285 g / 16.00 g/mol = 0.0178 mol

3) Look for smallest whole-number ratio:

carbon ⇒ 0.054 / 0.0178 = 3
hydrogen ⇒ 0.0711 / 0.0178 = 4
oxygen ⇒ 0.0178 / 0.0178 = 1

empirical fromula

= c3 h4 O

please do tell me if its wrong. il recheck into it and tell the correct answer.