How to Calculate the Number of Moles of SO2 Formed from Burning CS2 with Oxygen

Question:

If 114 grams of CS2 are burned in an excess of O2, how many moles of SO2 are formed?

A) 2.50

B) 2.99

C) 2.00

D) 1.00

E) 50.00

Answer:

The correct answer is option B) 2.99.

To calculate the number of moles of SO2 formed when 114 grams of CS2 are burned in an excess of O2, we first need to determine the number of moles of CS2. The molar mass of CS2 is 76.143 g/mol.

moles CS2 = 114 g / 76.143 g/mol = 1.497 mol

Next, we look at the balanced chemical equation for the reaction: CS2 + 3O2 → CO2 + 2SO2. The ratio between CS2 and SO2 is 1:2. Therefore, the number of moles of SO2 formed can be calculated as:

moles SO2 formed = 1.497 mol CS2 x 2 mol SO2 / 1 mol CS2 = 2.994 moles

So, when 114 grams of CS2 are burned in an excess of O2, 2.99 moles of SO2 are formed.