Solve the following question:
 
1. Carbon and oxygen combine in the ratio of \(3:8\) by mass to form carbon dioxide. What mass of oxygen gas would be required to react completely with \(15\) \(g\) of carbon?
 
Ratio of \(C\) : \(O\) by mass in carbon dioxide is:
 
 \(C + O_2 \to CO_2\)  
 
Carbon : Oxygen   
= 15 : \(x\)
 
\(x\) =