9. what is the percent composition of na₂co₃?% na =% c =% o =

Explanation:

Step1: Calculate molar mass of (Na_2CO_3)

Atomic masses: (Na = 22.99\space g/mol), (C = 12.01\space g/mol), (O = 16.00\space g/mol) (Molar\space mass\space of\space Na_2CO_3=(2\times22.99)+12.01+(3\times16.00)) (=45.98 + 12.01+48.00) (=105.99\space g/mol)

Step2: Calculate (%\space Na)

(%\space Na=\frac{2\times22.99}{105.99}\times100) (=\frac{45.98}{105.99}\times100\approx43.4%)

Step3: Calculate (%\space C)

(%\space C=\frac{12.01}{105.99}\times100\approx11.3%)

Step4: Calculate (%\space O)

(%\space O=\frac{3\times16.00}{105.99}\times100) (=\frac{48.00}{105.99}\times100\approx45.3%)

Answer:

(%\space Na\approx43.4%), (%\space C\approx11.3%), (%\space O\approx45.3%)