Acetylene gas is often used in welding torches because of the very high heat produced when it reacts with oxygen gas, producing carbon dioxide gas and water vapor. Calculate the moles of oxygen needed to produce 0.095 of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

0.12 mol O₂

Explanation:

Step 1: Write the balanced combustion reaction

C₂H₂ + 2.5 O₂ ⇒ 2 CO₂ + H₂O

Step 2: Establish the appropriate molar ratio

We want to know the moles of oxygen needed to produce 0.095 moles of carbon dioxide. The molar ratio of O₂ to CO₂ is 2.5:2.

Step 3: Calculate the moles of oxygen needed to produce 0.095 moles of carbon dioxide

0.095 mol CO₂ × 2.5 mol O₂/2 mol CO₂ = 0.12 mol O₂