The total volume of gas present at the end of the reaction : 100 cm³
<h3>Further explanation</h3>
Given
100cm³ of hydrogen is mixed with 25cm³ of oxygen
Reaction
2H₂(g) + O₂(g) ===> 2H₂O(l)
Required
The total volume of gas
Solution
From Avogadro's hypothesis, <em>at the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles </em>
Find limiting reactant
mol ratio H₂(g) : O₂(g) from equation : 2 : 1, so volume ratio = 2 : 1
O₂ as a limiting reactant(smaller ratio), so the remaining H₂(as excess reactant) = 100 cm³ - 50 cm³(reacting hydrogen) =50 cm³
H₂O formed from O₂ = 2 x volume O₂ = 2 x 25 = 50 cm³
2H₂(g) + O₂(g) ===> 2H₂O(l)
100 25 0
50 25 50
50 0 50
Total volume gas present : volume H₂ + volume H₂O = 50 + 50 = 100 cm³