Question

what is the balanced chemical equation occurring when potassium metal reacts with water to form potassium hydroxide and hydrogen gas? 2k(s) + 2h₂o(l) → 2koh(aq) + h₂(g) k(s) + h₂o(l) → k(oh)₂(aq) + h(g) k(s) + 2h₂o(l) → koh(aq) + h₂(g)

Explanation:

To determine the balanced chemical equation, we check the number of each atom on both sides. For potassium (K):

• Left side: In the first option, 2K. Right side: 2K in 2KOH.

For hydrogen (H):

• Left side: 2H₂O has 4H (2×2). Right side: 2KOH has 2H each, so 2×1 = 2H, and H₂ has 2H, total 4H.

For oxygen (O):

• Left side: 2H₂O has 2O. Right side: 2KOH has 2O (2×1).

The second option has incorrect formula (K(OH)₂ is wrong, KOH is correct) and H(g) is wrong (should be H₂). The third option has unbalanced K (1 on left, 1 on right but H and O are unbalanced: left has 4H, right has 1 (from KOH) + 2 (from H₂) = 3H; left has 2O, right has 1O). So the first option is balanced.

Answer:

A. $2\text{K}(\text{s}) + 2\text{H}_2\text{O}(\text{l})
ightarrow 2\text{KOH}(\text{aq}) + \text{H}_2(\text{g})$