Question

Carbon disulphide CS2, can be made from "by" product SO2. The overall reaction is: 5C + 2SO2 ------> CS2 + 4CO How much CS2 can be produced from 450kg of waste SO2 with excess of coke if the SO2 conversion is 82%. (For your reference the answer is 219.09kg)

Answer 1

Here 82% of 450 kg SO2, which is 369 kg is limiting reagent.

Answer 2

Answer: 219.09 kg

Explanation: $\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of $SO_2$ = 450 kg=450000 g

Molar mass of   $SO_2$= 64 g/mol

Putting values in above equation, we get:

$\text{Number of moles}=\frac{450000g}{64g/mol}=7031.25moles$

For the given chemical reaction, the equation follows:

$5C+2SO_2\rightarrow CS_2+N_2+4CO$

By Stoichiometry:

2 moles of $SO_2$ produces 1 mole of $CS_2$

So, 7031.25 moles of $SO_2$ react with = $\frac{1}{2}\times 7031.25=3515.62moles$  of $CS_2$

But the conversion is only 82%, thus moles of  $CS_2=\frac{82}{100}\times 3515.62=2882.80 moles$

Mass of $CS_2={\text {no of moles}}\times {\text {Molar mass}}$

Mass of $CS_2=2882.80\times 76g/mol=219093.4g=219.09kg$