1) 300cm³ of ethane were reacted with 120cm³ of oxygen and mixture exploded.
C₂H₄(aq) + 3O₂(aq)→ 2CO₂(g) + 2H₂O(g)
After reaction was complete, what was volume of unreacted gas.
(volumes are at room temperature and pressure)
Step IV
Cross multiply

Step IV
Unreacted C₂H₄ =