Question

H₂SO₄ + HI → H₂S + I₂ + H₂O

which option shows a correctly balanced chemical equation?

a. H₂SO₄ + HI → H₂S + I₂ + H₂O

b. 2H₂SO₄ + 4HI → 2H₂S + I₂ + 4H₂O

c. H₂SO₄ + 2HI → H₂S + I₂ + 2H₂O

d. 2H₂SO₄ + HI → H₂S + 2I₂ + 2H₂O

Answer 1

To check if a chemical equation is balanced, each element must have the same number of atoms on both sides. Among the examples provided, only options b in both sets are balanced chemical equations.

The correct answer is B.

Step-by-step explanation:

To determine if each chemical equation is balanced, we must ensure that the number of atoms of each element is the same on both sides of the equation. When inspecting the provided equations:

• a. 2Hg(e) + O2(g) → Hg2O2 (s) is not balanced; it lacks enough oxygen on the right side to match the left.
• b. C2H4(g) + 2O2(g) → 2CO2(g) + 2H2O(l) is balanced; the number of atoms for each element is equal on both sides.
• c. Mg(NO3)2(s) + 2Li(s) → Mg(s) + 2LiNO3(s) is not balanced; the right side has extra oxygen and nitrogen not accounted for on the left.

For the provided equations:

• a. 2Na(s) + O2(g) → 2Na2O(s) can't be assessed due to a typo. However, assuming it should be 2Na(s) + O2(g) → 2Na2O(s), it's not balanced because the sodium atoms are not equal on both sides.
• b. CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) is balanced, maintaining equal atoms on each side.
• c. AgNO3(aq) + 2KCl(aq) → AgCl(s) + KNO3(aq) is not balanced as it has unequal potassium and nitrate ions on each side.