Question

what is the elemental composition of acetic acid, hc₂h₃o₂? report the mass percent of each element to 4 significant digits and do not include units.
% h
% c
% o

Explanation:

Step1: Calculate molar mass of \(HC_2H_3O_2\)

Molar mass of \(H\) is \(1.008\ g/mol\), \(C\) is \(12.01\ g/mol\), \(O\) is \(16.00\ g/mol\).
\(M = 1.008\times(1 + 3)+12.01\times2+16.00\times2\)
\(M = 4.032+24.02+32.00=60.052\ g/mol\)

Step2: Calculate mass percent of \(H\)

Mass of \(H\) in \(HC_2H_3O_2\) is \(4\times1.008 = 4.032\ g/mol\)
\(\%\ H=\frac{4.032}{60.052}\times100\approx6.714\)

Step3: Calculate mass percent of \(C\)

Mass of \(C\) in \(HC_2H_3O_2\) is \(2\times12.01 = 24.02\ g/mol\)
\(\%\ C=\frac{24.02}{60.052}\times100\approx40.00\)

Step4: Calculate mass percent of \(O\)

Mass of \(O\) in \(HC_2H_3O_2\) is \(2\times16.00 = 32.00\ g/mol\)
\(\%\ O=\frac{32.00}{60.052}\times100\approx53.29\)

Answer:

6.714
40.00
53.29