The pH of a solution in which [H30+]= 1.5×10^-3M
The correct answer and explanation is :
To calculate the pH of a solution, we use the formula:
[
\text{pH} = -\log [H_3O^+]
]
Where:
- ([H_3O^+]) is the concentration of hydronium ions in the solution.
In the given problem, the concentration of hydronium ions ([H_3O^+]) is (1.5 \times 10^{-3} \, M).
Step 1: Apply the formula
[
\text{pH} = -\log (1.5 \times 10^{-3})
]
Step 2: Calculate the logarithm
Using a calculator to find the logarithm of (1.5 \times 10^{-3}):
[
\log (1.5 \times 10^{-3}) \approx -2.8239
]
Step 3: Determine the pH
[
\text{pH} = -(-2.8239) = 2.8239
]
Thus, the pH of the solution is approximately 2.82.
Explanation:
The pH scale measures the acidity or basicity of a solution based on the concentration of hydrogen ions ((H_3O^+)) present. The lower the pH, the more acidic the solution, which corresponds to a higher concentration of hydrogen ions. A pH of 7 is considered neutral (neither acidic nor basic), with values lower than 7 indicating acidity and values greater than 7 indicating basicity.
In this case, the concentration of (H_3O^+) ions is (1.5 \times 10^{-3} \, M), which is relatively high compared to neutral water, where the concentration of (H_3O^+) is (1.0 \times 10^{-7} \, M). Since this value is greater than 7, the solution is acidic, and the pH is calculated to be 2.82, confirming that the solution is indeed acidic.
The pH of a solution is an essential property, as it can affect chemical reactions, biological processes, and the solubility of various compounds.