Question

The balanced chemical equation for potassium reacting with water is:

• A. $\text{K}\text{(s)}+2{\text{H}}_2\text{O(l)}\to \text{KOH(aq)}+{\text{H}}_2\text{(g)}$
• B. $2\text{K}\text{(s)}+{\text{H}}_2\text{O(l)}\to 2\text{KOH(aq)}+{\text{H}}_2\text{(g)}$
• C. $\text{K}\text{(s)}+{\text{H}}_2\text{O}\text{(l)}\to \text{KOH(aq)}+{\text{H}}_2\text{(g)}$
• D. $2\text{K}\text{(s)}+2{\text{H}}_2\text{O}\text{(l)}\to 2\text{KOH(aq)}+{\text{H}}_2\text{(g)}$

Answer 1

The correct option is D $2\text{K}\text{(s)}+2{\text{H}}_2\text{O}\text{(l)}\to 2\text{KOH(aq)}+{\text{H}}_2\text{(g)}$

Potassium reacts with water to form potassium hydroxide along with hydrogen. The chemical equation for this reaction is given below:

$\text{K}\text{(s)}+{\text{H}}_2\text{O}\text{(l)}\to \text{KOH(aq)}+{\text{H}}_2\text{(g)}$

We can see that: Reactant Product

Elements Symbol	No. of atoms	Elements Symbol	No. of atoms
K	1	K	1
H	2	H	3
O	1	O	1

Now in order to balance the equation the number of atoms on both reactants and the products side should be equal. By applying hit and trial method the balanced equation of the given reaction is:
$\text{2K}\text{(s)}+{\text{2H}}_2\text{O}\text{(l)}\to \text{2KOH (aq)}+{\text{H}}_2\text{(g)}$