<span>When you have to balance an equation it means that you have to balance both parts of equation so that the numbers of each elements will have the same amount. According to this rule, it is quite easy to distinguish unbalanced reaction, and the answer is a) HBr + Ca(OH)2 → CaBr2 + H2O as you can see that amount of oxygen on both sides is not the same.</span>
HNO₃ + H₂S → S + NO + H₂<span>O
Assign Oxidation Number:
L.H.S R.H.S
N in HNO</span>₃ = +5 +2 = N in NO
S in H₂S = -2 0 = S in S
Write Half cell Reactions:
Reduction Reaction:
3e⁻ + HNO₃ → NO -------(1)
Oxidation Reaction:
H₂S → S + 2e⁻ -------(2)
Multiply eq. 1 with 2 and eq. 2 with 3 to balance electrons.
6e⁻ + 2 HNO₃ → 2 NO
3 H₂S → 3 S + 6e⁻
Cancel e⁻s,
______________________________
2 HNO₃ + 3 H₂S → 2 NO + 3 S + H₂O
Balance Oxygen Atoms by multiplying H₂O with 4, Hydrogen atoms will automatically get balance.
2 HNO₃ + 3 H₂S → 2 NO + 3 S + 4H₂O
M1V1 = M2V2
M1 = 3.000 M
V1 = 0.8000 L
M2 = ?
V2 = 2.00 L
M2 = M1V1/V2 = (3.000 M)(0.8000 L)/(2.00 L) = 1.20 M
It depends on the pH level of the water.