Enter a balanced chemical equation for the reaction between potassium metal and liquid water.

2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g) ↑

Explanation:

1) Word equation (given)

Potassium + water →?

2) Kind of reaction

Potassium is an alkali metal.

This is a single replacement reaction.

Alkali metals is the group of metals in the group 1 of the periodic table. These are the most active metals, meaning that they react violently with water releasing hydrogen gas.

Alkali metals can lose an electron to form compounds with oxidation number + 1.

The general equation for the reaction of an alkali metal and water is:

Metal + Water → hydroxide + gaseous hydrogen

X + H₂O → XOH (aq) + H₂ (g) ↑

3) Chemical equation

K (s) + H₂O (l) → KOH (aq) + H₂ (g) ↑

4) Balance

2K (s) + 2H₂O (l) → 2KOH (aq) + H₂ (g) ↑

There is the same number of each atom on both sides: 2 K in the left and in the right, 4 H in the left and in the right, and 2 oxygen in the left and in the right. So, the equation is balanced.