The moles of oxygen required to completely react with 1-mole acetylene is 2.5 mol.
The moles of reactant and product in a chemical reaction to the whole number ratio is given by the stoichiometric coefficient of the balanced chemical equation.
<h3>Computation for the moles of oxygen</h3>
The balanced chemical equation for the reaction is :

From the balanced chemical equation, the 2 moles of acetylene react with 5 moles of oxygen.
The moles of oxygen react with 1 mole of acetylene are:

The moles of oxygen required to completely react with 1-mole acetylene is 2.5 mol.
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