3) Calculate the [tex]$pH$[/tex] of the following solutions:

a) [tex]$[ H^+]=1.2 \times 10^{-3} \, M$[/tex]

b) [tex][tex]$[ H^+]=4.63 \times 10^{-5} \, M$[/tex][/tex]

c) [tex]$[ H^+]=1 \times 10^{-7} \, M$[/tex]

d) [tex]$[ H^+]=8.3 \times 10^{-10} \, M$[/tex]



Answer :

Let's calculate the pH of each given solution step-by-step.

### What is pH?
The pH of a solution is a measure of its acidity or basicity and is defined by the formula:
[tex]\[ \text{pH} = -\log_{10} [\text{H}^+] \][/tex]
where [tex]\([\text{H}^+]\)[/tex] is the concentration of hydrogen ions in moles per liter (M).

### Given Data
We have the following concentrations of hydrogen ions for different solutions:
a) [tex]\([\text{H}^+] = 1.2 \times 10^{-3} \text{M}\)[/tex]
b) [tex]\([\text{H}^+] = 4.63 \times 10^{-5} \text{M}\)[/tex]
c) [tex]\([\text{H}^+] = 1 \times 10^{-7} \text{M}\)[/tex]
d) [tex]\([\text{H}^+] = 8.3 \times 10^{-10} \text{M}\)[/tex]

### Calculations

#### Part (a)
For [tex]\([\text{H}^+] = 1.2 \times 10^{-3} \text{M}\)[/tex],
[tex]\[ \text{pH} = -\log_{10} (1.2 \times 10^{-3}) \][/tex]

The result is:
[tex]\[ \text{pH} \approx 2.92 \][/tex]

#### Part (b)
For [tex]\([\text{H}^+] = 4.63 \times 10^{-5} \text{M}\)[/tex],
[tex]\[ \text{pH} = -\log_{10} (4.63 \times 10^{-5}) \][/tex]

The result is:
[tex]\[ \text{pH} \approx 4.33 \][/tex]

#### Part (c)
For [tex]\([\text{H}^+] = 1 \times 10^{-7} \text{M}\)[/tex],
[tex]\[ \text{pH} = -\log_{10} (1 \times 10^{-7}) \][/tex]

The result is:
[tex]\[ \text{pH} = 7.00 \][/tex]

#### Part (d)
For [tex]\([\text{H}^+] = 8.3 \times 10^{-10} \text{M}\)[/tex],
[tex]\[ \text{pH} = -\log_{10} (8.3 \times 10^{-10}) \][/tex]

The result is:
[tex]\[ \text{pH} \approx 9.08 \][/tex]

### Summary
The calculated pH values for the given solutions are:
a) [tex]\(\text{pH} \approx 2.92\)[/tex]
b) [tex]\(\text{pH} \approx 4.33\)[/tex]
c) [tex]\(\text{pH} = 7.00\)[/tex]
d) [tex]\(\text{pH} \approx 9.08\)[/tex]