Question

question 10 (1 point)
what is the hydronium ion concentration of a solution at 25 c with a poh of 4.70?
9.01 × 10^{-3} m
9.18 × 10^{-5} m
5.01 × 10^{-10} m

Explanation:

Step1: Calculate pH

At \(25^{\circ}\text{C}\), \(pH + pOH=14\). Given \(pOH = 4.70\), then \(pH=14 - 4.70=9.30\)

Step2: Calculate \([H_3O^+]\)

The formula for \(pH\) is \(pH=-\log[H_3O^+]\). Rearranging for \([H_3O^+]\) gives \([H_3O^+]=10^{-pH}\). Substituting \(pH = 9.30\), we have \([H_3O^+]=10^{-9.30}\)
Using the property \(a^{m + n}=a^m\times a^n\), \(10^{-9.30}=10^{-10 + 0.70}=10^{0.70}\times10^{-10}\approx5.01\times 10^{-10}\text{ M}\)

Answer:

C. \(5.01\times 10^{-10}\text{ M}\)