Step-by-step explanation:
According to the problem, hydrochloric acid and oxygen gas form water and chlorine gas. The unbalanced equation will be:
__ HCl + __ O₂ ---> __ H₂O + __ Cl₂
We have two atoms of O on the left and just one on the right. We can change the coefficient for H₂O to balance the O.
__ HCl + __ O₂ ---> 2 H₂O + __ Cl₂
Now we have four atoms of H on the right and just one on the left. We can change the coefficient for HCl to balance the H.
4 HCl + __ O₂ ---> 2 H₂O + __ Cl₂
And finally we have four atoms of Cl on the left and just two on the right. We can change the coefficient for Cl₂ to balance the Cl. The balanced equation is:
4 HCl + O₂ ---> 2 H₂O + 2 Cl₂
According to the coefficients of the equation, 4 moles of HCl will react with 1 mol of O₂ to produce 2 moles of H₂O and 2 moles of Cl₂. So 1 mol of O₂ will be required to produce 2 moles of H₂O. We can use that ratio to find the number of moles of O₂ that are required to produce 7.03 moles of H₂O.
1 mol of O₂ : 2 moles of H₂O molar ratio
moles of O₂ = 7.03 moles of H₂O * 1 mol of O₂/(2 moles of H₂O)
moles of O₂ = 3.52 moles
Answer: 3.52 moles of oxygen gas are required to produce 7.03 moles of water.