Question

In Chemistry, the pH of a solution is defined by pH = -log₁0[H +), where H+ is the hydrogen ion concentration of the solution in moles per liter. At a

river, the pH was measured as 2.36 x 10⁻7 mol/L. A year later at the same river the pH was measured as 1.41 x 10⁻8mol/L. How much did the pH
increased in one year?
a) 1.95

b) 6.95

c) 7.95

d) 9.95

Answer 1

The change in pH over one year is calculated by finding the difference of final pH (7.85) and initial pH (6.63), which is 1.22. None of the provided options match this calculated increase.

Step-by-step explanation:

To calculate how much the pH increased over one year for the river, we need to individually calculate the initial and final pH values using the respective hydrogen ion concentrations and then find the difference between these two pH values.

The initial pH is calculated as follows:

pHinitial = -log(2.36 × 10⁻⁷)
= -(-6.63)
= 6.63

The final pH is calculated as:

pHfinal = -log(1.41 × 10⁻⁻)
= -(-7.85)
= 7.85

To find the increase in pH:

pH increase = pHfinal - pHinitial
= 7.85 - 6.63
= 1.22

Looking at the given options, none of the provided choices (a) 1.95, (b) 6.95, (c) 7.95, (d) 9.95 correctly represent the calculated pH increase of 1.22. Therefore, none of the given options is correct for the calculated pH increase in one year.