Question

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 acetylene needed to produce of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.

Answer 1

2.25 moles ≈ 2.3 moles

Step-by-step explanation:

Full Question:

Acetylene C2H2 gas is often used in welding torches because of the very high heat produced when it reacts with oxygen O2 gas, producing carbon dioxide gas and water vapor. Calculate the moles of oxygen needed to produce 1.5mol of water. Be sure your answer has a unit symbol, if necessary, and round it to significant digits.

First off, let's put the equation of the reaction sown;

C2H2 + O2 → H2O + CO2

Upon balancing, we have;

2C2H2 + 3O2 → 2H2O + 4CO2

So from the equation;

3 mole of oxygen is required in order to produce 2 mole of water vapour.

The question asks to calculate moles of oxygen needed to produce 1.5mol of water

This leads us to;

3 moles = 2 moles

x moles = 1.5 moles

x = ( 1.5 * 3 ) / 2

x = 4.5 / 2 = 2.25 moles ≈ 2.3 moles