Question

Unstable potassium oxide reacts with water vapor in the air to produce potassium hydroxide:

K2O + H2O → KOH

What, if anything, should be done to balance this chemical equation?
A) Nothing. It is balanced.
B) Put a "2" in front of the KOH.
C) Put a "4" in front of the KOH.
D) Put ".5" in front of both K2O and H2O.

Answer 1

Answer:

B) Put a "2" in front of the KOH.

Explanation:

We are given;

• The unbalanced equation;

        K₂O + H₂O → KOH

Why is it unbalanced?

• The equation is unbalanced because the number of atoms of each elements are not equal on both sides of the equation.
• That is; Reactant side; 2 K atoms, 2 H atoms, and 2 O atoms while the product side has 1 K atom, 1 O atom and 1 H atom.

How should we make the equation balanced?

• In order to balance an equation we put appropriate coefficients in front of reactants or products.
• In this case, we can balance the equation by putting 1 in front of K₂O, 1  in front H₂O and 2 in front of KOH which simply means putting a "2" in front of KOH

• Therefore, the balanced equation is;

       K₂O + H₂O → 2KOH