Answer:
The answer to your question is 27.3 %
Step-by-step explanation:
Percent by mass = ?
Process
1.- Calculate the atomic mass of carbon using the periodic table
Atomic mass = 12g
2.- Calculate the molecular mass of CO₂.
Carbon = 12
Oxygen = 16 x 2 = 32
Total = 12 + 32 = 44g
3.- Calculate the percent by mass of carbon using proportions
44g -------------------- 100%
12 g ------------------- x
x = (12 x 100) / 44
x = 1200 / 44
x = 27.3 %