Answer :
Answer: 17.9 g
Explanation:
1) Chemical equation:
H₂ (g) + Cl₂ (g) → 2HCl (g)
2) mole ratios:
1 mol H₂ : 1 mol Cl₂ : 2 mol HCl
3) Since, the pressure and temperature conditions do not change, the same proportion is valid for the volumes. Then:
1 liter H₂ / 2 liter HCl = 5.15 liter H₂ / x
⇒ x = 5.5 × 2 / 1 = 11 liter HCl
4) Calculate the number of moles of HCl in 11 liter of HCl at STP
At STP, 1 mol of gas = 22.4 liter
⇒ 11 liter × 1mol / 22.4 liter = 0.491 mol HCl
5) Use the molar mass to convert 0.491 mol to grams
molar mass of HCl = 1.008 g/mol + 35.453 g/mol = 36.461 g/mol
mass in grams = nuumber of moles × molar mass = 36.461 g/mol × 0.491 mol = 17.90 g.