Question

The equation for the pH of a substance is pH = –log[H+], where H+ is the concentration of hydrogen ions. A basic solution has a pH of 11.2. An acidic solution has a pH of 2.4. What is the approximate difference in the concentration of hydrogen ions between the two solutions?

Answer 1

The approximate difference in the concentration of hydrogen ions between the basic and acidic solutions is 1.58 × 10^-9.

Step-by-step explanation:

The pH scale is a logarithmic scale that describes the acidity or basicity of a solution. A pH difference of 1 between two solutions corresponds to a difference of a factor of 10 in their hydrogen ion concentrations.

Given that a basic solution has a pH of 11.2 and an acidic solution has a pH of 2.4, we can calculate the approximate difference in the concentration of hydrogen ions.

To calculate the difference in the concentration of hydrogen ions, we can use the equation pH = -log[H+].

For the basic solution with a pH of 11.2:

pH = -log[H+]

11.2 = -log[H+]

Using the logarithmic scale, we can calculate the concentration of hydrogen ions:

H+ = 10^-pH

H+ = 10^-11.2

H+ ≈ 6.31 × 10^-12

For the acidic solution with a pH of 2.4:

pH = -log[H+]

2.4 = -log[H+]

Using the logarithmic scale, we can calculate the concentration of hydrogen ions:

H+ = 10^-pH

H+ = 10^-2.4

H+ ≈ 0.004

Therefore, the approximate difference in the concentration of hydrogen ions between the two solutions is:

6.31 × 10^-12 / 0.004 ≈ 1.58 × 10^-9

Answer 2

0.003981 . . . . moles per liter

Step-by-step explanation:

The concentration of H+ ions in the acid will be ...

10^(-2.4) ≈ 0.003981 . . . . moles per liter

The concentration of H+ ions in the base will be ...

10^-11.2 ≈ 0.000 000 000 006310 . . . . moles per liter

To a few decimal places, the difference is ...

0.003981 . . . . moles per liter

_____

The two numbers differ by about 9 orders of magnitude, so the value of the difference between the larger and the smaller is essentially the value of the larger number. The smaller one, by comparison, can be considered to be zero (for subtraction purposes).