Question

Carbon dioxide (CO2) is a gaseous compound. Calculate the percent composition of this compound. Answer using three significant figures. What is the percent by mass of carbon? %

Answer 1

Carbon dioxide is a gaseous molecule made up of the elements, C and O. Each mole of carbon dioxide has one mole C and two mole oxygen atoms.

Molar mass of carbon dioxide ($CO_{2}$)=$(1 * 12.01\frac{g}{mol}) +(2* 16\frac{g}{mol})=44.01\frac{g}{mol}$

Percentage by mass of carbon = $\frac{(1*12.01\frac{g}{mol}) }{44.01\frac{g}{mol} } *100=27.3%$

Percentage by mass of oxygen = $\frac{(2*16\frac{g}{mol})}{44.01\frac{g}{mol} } *100=72.7%$

Therefore C is 27.3 % and O is 72.7 % by mass in 1 mol CO$_{2}$

Answer 2

Carbon dioxide (CO2) is a gaseous compound. Calculate the percent composition of this compound. Answer using three significant figures.

What is the percent by mass of carbon? % Answer- 27.3

What is the percent by mass of oxygen? %  Answer- 72.7