When the following equation is balanced using the smallest possible integers, what is the exponent of Al in the reaction quotient expression?

Question

When the following equation is balanced using the smallest possible integers, what is the exponent of Al in the reaction quotient expression?

Al(s) + NaOH(aq) + H₂O(l) <=> Na(Al(OH)₄)(aq) + H₂(g)

Answer is: 0

Why is the answer 0 when the balanced equation is:

2 Al(s) + 2 NaOH(aq) + 6 H2O(l) <=> 2 Na[Al(OH)4](aq) + 3 H2(g)

please explain how you got to 0, thank you.

Answer 1

The reaction quotient is the concentration of the products divided by the concentration of the reactants, each raised to the exponent equal to the coefficient in the balanced equation. Since Al is present as a SOLID on the reactant side, the value of the concentration is unity (1), and so the exponent would be ZERO, since anything raised to the 0 power is 1.

Q = [NaAl(OH)4]² [H2]³ / [Al]⁰ [NaOH] [H2O]⁰