Question

14 fill in the missing words
in an acidic solution the concentration of hydronium ions is
than the concentration
of hydroxide ions. the more acidic the solution is, the
is its ph.

Explanation:

1. For the first blank: In an acidic solution, by definition, the concentration of hydronium ions ($\ce{H_3O^+}$) is greater than the concentration of hydroxide ions ($\ce{OH^-}$) because acids donate protons which increase the hydronium ion concentration.
2. For the second blank: The pH scale is defined as $\text{pH} = -\log_{10}[\ce{H_3O^+}]$. As the concentration of hydronium ions increases (more acidic), the value of $-\log_{10}[\ce{H_3O^+}]$ decreases. So the more acidic the solution, the lower its pH.

Answer:

First blank: greater; Second blank: lower