Q21GATE 2007MCQ

50 g of $CO_{2}$ and 25 g of $CH_{4}$ are produced from the decomposition of municipal solid waste (MSW) with a formula weight of 120 g. What is the average per capita green house gas production in a city of 1 million people with a MSW production rate of 500 ton/day ?

🚀 Solve in Practice Mode

📖 Explanation

We know that both $CO_{2}$ and $CH_{4}$ are green house gases. $\therefore$ Total green house gases produced by 120 gm of MSW = 50 g $CO_{2}$ +25 g of $CH_{4}$ =75 gm 500 ton of MSW will produce green house gases

\begin{aligned} &=500\times 10^{6}\times \frac{75}{120} \\ &= 312.5\times 10^{6}\: g/day \end{aligned}

Per capita average production of green house gases

\begin{aligned} &=\frac{312.5\times 10^{6}}{1\times 10^{6}}\: g/day \\ &=312.5\: g/day\approx 313\: g/day \end{aligned}

Q22GATE 2006MCQ

The composition of a certain MSW sample and specific weights of its various components are given below : Specific weight ( $kg/m^3$ ) of the MSW sample is

🚀 Solve in Practice Mode

📖 Explanation

Let specific weight of MSW sample is X kg/ $m^{3}$

\begin{aligned} \text{Now,} \; \; \rho &= \frac{Total\; weight}{Total\; volume}\\ \frac{100}{X}&=\frac{50}{300}+\frac{30}{500}+\frac{10}{65}+\frac{10}{125} \\ \therefore \; \;\frac{100}{X} &=0.4605 \\ \therefore \;\; X &=217.15\; kg/m^{3}\approx 217\: kg/m^{3} \end{aligned}