A sample of hydrogen sulfide ($H_{2}S$) has a volume of $50{cm}^3$ at room temperature and pressure. The sample is burned completely in $1500{cm}^3$ of air. The final mixture is cooled to room temperature and pressure. The equation for the complete combustion is: $2\text{H}_2\text{S}(g) + 3\text{O}_2(g) \rightarrow 2\text{SO}_2(g) + 2\text{H}_2\text{O}(l)$ Calculate the total volume of gas in the final mixture. Assume that air contains $21\%$ by volume of oxygen.