A 4.05 g sample of a compound containing only C, H, and O was burned completely. The only combustion products were 10.942 g CO₂ and 4.476 g H₂O. What is the empirical formula of the compound?

Question

Quizplus · Accepted Answer

The empirical formula is CH2O.The combustion reaction is:C_xH_yO_z + (x + y/4 - z/2) O₂ → x CO₂ + y/2 H₂OFrom the given masses, we can calculate the moles of each product:moles of CO₂ = 10.942 g / 44.01 g/mol = 0.2486 molmoles of H₂O = 4.476 g / 18.02 g/mol = 0.2484 molFrom the stoichiometry of the reaction, we can see that the moles of C, H, and O in the compound are:moles of C = moles of CO₂ = 0.2486 molmoles of H = 2 x moles of H₂O = 2 x 0.2484 mol = 0.4968 molmoles of O = moles of CO₂ + moles of H₂O - moles of C - moles of H = 0.2486 mol + 0.2484 mol - 0.2486 mol - 0.4968 mol = 0.2484 molTherefore, the empirical formula of the compound is CH₂O.

A 405 G Sample of a Compound Containing Only C, H