Q.10.9 - An Introduction to General, Organic, and Biological Chemistry

Question

Identify each of the solutions in problem 10.88 as acidic, basic, or neutral. 

Step-by-Step Solution

Answer

a. Neutral

b. acidic

c. acidic 

d. acidic 

Step 1: Given Information

Acidic solutions are estimated to have lower pH values than basic or alkaline solutions. pH or "potential of hydrogen" is a scale used to specify the acidity or basicity of a fluid solution. 

$$\begin{gathered} \mathrm{a}.\left[{\mathrm{OH}}^{-}\right]=1.0\times {10}^{-7}\mathrm{M} \\ \mathrm{b}.\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]=4.2\times {10}^{-3}\mathrm{M} \\ \mathrm{c}.\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]=0.0001\mathrm{M} \\ \mathrm{d}.\left[{\mathrm{OH}}^{-}\right]=8.5\times {10}^{-9}\mathrm{M} \end{gathered}$$

Step 2: Explanation

A solution is acidic if its pH is less than $7$. A solution is basic if its pH is greater than $7$. A solution is neutral if its pH is equal to $7$.

Hence, applying the above logic the solutions are -

a.$\left[{\mathrm{OH}}^{-}\right]=1.0\times {10}^{-7}\mathrm{M}$ is Neutral

b.$\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]=4.2\times {10}^{-3}\mathrm{M}$ is acidic 

c.$\left[{\mathrm{H}}_3{\mathrm{O}}^{+}\right]=0.0001\mathrm{M}$ is acidic  

d.$\left[{\mathrm{OH}}^{-}\right]=8.5\times {10}^{-9}\mathrm{M}$ is acidic