A volume of $100\,\text{cm}^3$ of ethene is burned completely in $400\,\text{cm}^3$ of oxygen. The volumes of both gases are measured at r.t.p. What is the final volume of gas in the mixture measured at r.t.p.?
- A$200\,\text{cm}^3$
- B$250\,\text{cm}^3$
- C$300\,\text{cm}^3$
- D$500\,\text{cm}^3$