Question

the ph of a solution of hbr is 3.21 at 25°c. what is the h+ concentration in this solution?

Explanation:

Step1: Recall the pH formula

The formula for pH is \(pH = -\log[H^{+}]\). We need to solve for \([H^{+}]\). Rearranging the formula gives \([H^{+}]=10^{-pH}\).

Step2: Substitute the given pH value

Given \(pH = 3.21\), substitute into the formula: \([H^{+}]=10^{- 3.21}\).
Using the property \(a^{m + n}=a^{m}\times a^{n}\), we can write \(10^{-3.21}=10^{-(3 + 0.21)}=10^{-3}\times10^{- 0.21}\).
We know that \(10^{-0.21}\approx0.617\) (by using a calculator for the antilogarithm).
So, \(10^{-3}\times10^{-0.21}=6.17\times10^{-4}\space M\).

Answer:

\(6.17\times 10^{-4}\space M\)