Question

chemical equations
c₂h₅oh(l) + □ o₂(g) ⟶ 2co₂(g) + □ h₂o(l) + energy
2 agcl(s) ⟶ 2 ag(s) + cl₂(g)
□ agno₃(aq) + zn(s) ⟶ □ ag(s) + zn(no₃)₂(aq)
□ bacl₂(aq) + al₂(so₄)₃(aq) ⟶ 3baso₄(s) + □ alcl₃(aq)
h₂(g) + i₂(g) ⟶ □ hi(g)

Explanation:

Step1: Balance first equation (C₂H₅OH)

C: 2 on left → 2 CO₂ (done). H: 6 on left → 3 H₂O. O: Left: 1 (C₂H₅OH) + 2x(O₂); Right: 4(CO₂) +3(H₂O)=7 → 2x=6 → x=3.

Step2: Check second equation (AgCl)

Given 2AgCl→2Ag+Cl₂: Ag (2=2), Cl (2=2) → balanced.

Step3: Balance third equation (AgNO₃+Zn)

Zn: 1 on left → 1 Zn(NO₃)₂. NO₃⁻: 2 on right → 2 AgNO₃. Ag: 2 on left → 2 Ag.

Step4: Balance fourth equation (BaCl₂+Al₂(SO₄)₃)

SO₄²⁻: 3 on left → 3 BaSO₄. Ba: 3 on right →3 BaCl₂. Cl⁻:6 on left →2 AlCl₃. Al:2 on left=2 on right.

Step5: Balance fifth equation (H₂+I₂)

H:2, I:2 → 2 HI.

Answer:

First equation: 3 (O₂), 3 (H₂O)
Second equation: Already balanced (2,2)
Third equation: 2 (AgNO₃), 2 (Ag)
Fourth equation:3 (BaCl₂),2 (AlCl₃)
Fifth equation:2 (HI)