Question

In Step 5, you will calculate H+/OH– ratios for more extreme pH solutions. Find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 2. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C. What is the concentration of H+ ions at a pH = 2? mol/L What is the concentration of OH– ions at a pH = 2? mol/L What is the ratio of H+ ions to OH– ions at a pH = 2? : 1

Answer 1

The ratio of H⁺ ions to OH⁻ ions at a pH = 2 is 10¹⁰

Further explanation

Given

ph = 2

Required

The concentration of H⁺ and OH⁻ ions

Solution

• The concentration of H⁺ ions

pH=-log[H⁺]

2=-log[H⁺]

[H⁺]=10⁻²

• The concentration of OH⁻ ions

pH+pOH=14

pOH=14-2

pOH=12

pOH=-log[OH⁻]

12=-log[OH⁻]

[OH⁻]=10⁻¹²

• The ratio of H⁺ ions to OH⁻ ions at a pH = 2

$\tt \dfrac{10^{-2}}{10^{-12}}=10^{10}$