Question

When ethyne (C₂H₂) reacts with O₂ in a combustion reaction, the products of the combustion are CO₂ and H₂O. Which combination of reactants would react completely with nothing left over of either reactant?

1) 2C₂H₂ + 5O₂
2) 2C₂H₂ + 7O₂
3) 4C₂H₂ + 9O₂
4) 4C₂H₂ + 11O₂

Answer 1

Option 1) 2C₂H₂ + 5O₂ would react completely with nothing left over of either reactant.

Step-by-step explanation:

To determine which combination of reactants would react completely in the combustion of ethyne, we need to balance the equation for the reaction:

C₂H₂ + O₂ → CO₂ + H₂O

The equation must have the same number of each element on both sides. The balanced equation is:

2C₂H₂ + 5O₂ → 4CO₂ + 2H₂O

Therefore, option 1) 2C₂H₂ + 5O₂ would react completely with nothing left over of either reactant.