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 of water. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

0.225 mol = 0.23 mol to 2 significant figures

Explanation:

Calculate the moles of oxygen needed to produce 0.090 mol of water

The equation of the reaction is given as;

2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O

From the equation of the reaction;

5 mol of O2 produces 2 mol of H2O

x mol of O2 produces 0.090 mol of H2O

5 = 2

x = 0.090

x = 0.090 * 5 / 2

x = 0.225 mol