Question

When coal is burned, the sulfur it contains is converted into sulfur dioxide. This SO2 is a serious pollutant, so it needs to be removed before it escapes from the stack of a coal fired plant. One way to remove the SO2 is to add limestone, which contains calcium carbonate, CaCO3, to the coal before it is burned. The heat of the burning coal converts the CaCO3 to calcium oxide, CaO. The calcium oxide reacts with the sulfur dioxide in the following reaction:

2CaO + 2SO2 + O2 → 2CaSO4

The solid calcium sulfate does not escape from the stack as the gaseous sulfur dioxide would. What mass of calcium sulfate forms for each 1893 kg of SO2 removed by this technique

Answer 1

Molar mass of SO2 = 1*MM(S) + 2*MM(O)

= 1*32.07 + 2*16.0

= 64.07 g/mol

mass of SO2 = 1893 Kg = 1893000 g

mol of SO2 = (mass)/(molar mass)

= 1893000/64.07

= 29545.81 mol

From balanced chemical reaction, we see that

when 2 mol of SO2 reacts, 2 mol of CaSO4 is formed

mol of CaSO4 formed = moles of SO2

= 29545.81 mol

Molar mass of CaSO4 = 1*MM(Ca) + 1*MM(S) + 4*MM(O)

= 1*40.08 + 1*32.07 + 4*16.0

= 136.15 g/mol

mass of CaSO4 = number of mol * molar mass

= 29545.8093*136.15

= 4022662 g

= 4023 Kg

Answer: 4023 Kg