Answer:
4HCl(g) + O2(g) → 2Cl2(g) + 2H2O(g)
Explanation:
Step 1: Data given
Number of moles hydrogen chloride (HCl) = 4.0 moles
Number of moles oxygen gas (O2) = 1.0 moles
Number of moles chlorine gas (Cl2) produced = 2.0 moles
Number of moles of water gas (H20) = 2.0 moles
Step 2: The unbalanced equation
HCl(g) + O2(g) → Cl2(g) + H2O(g)
Step 3: Balancing the equation
HCl(g) + O2(g) → Cl2(g) + H2O(g)
On the left side we have 2x O (in O2), on the right side we have 1x O (in H2O).
To balance the amount of O on both sides, we have to multiply H2O on the right side by 2.
HCl(g) + O2(g) → Cl2(g) + 2H2O(g)
On the left side we have 1x H (in HCl), on the right side we have 4x H (in 2H2O). To balance the amount of H on both sides, we have to multiply HCl on the left side by 4.
4HCl(g) + O2(g) → Cl2(g) + 2H2O(g)
On the left side we have 4x Cl (in 4HCl), on the right side we have 2x Cl (in Cl2). To balance the amount of Cl on both sides,we have to multiply Cl2 by 2. Now the equation is balanced.
4HCl(g) + O2(g) → 2Cl2(g) + 2H2O(g)
This means for 4 moles Hcl we need 1 mol O2 to react to produce 2 moles Cl2 and 2 moles H2O