A solution is made by mixing 0.05 mL of 1.0 M HCl with 999.95 mL of pure water.Calculate the pH of the resulting solution (assume the total volume is 1.0 L).
A)2)7
B)4)3
C)9)7
D)7)0
E)5)0

Question

Quizplus · Accepted Answer

The pH of the solution can be calculated by first determining the concentration of HCl in the final solution. The initial moles of HCl are $0.05 \, \text{mL} \times 1.0 \, \text{M} = 0.05 \, \text{mmol}$. Since the final volume is 1.0 L (or 1000 mL), the concentration of HCl in the final solution is $0.05 \, \text{mmol} / 1000 \, \text{mL} = 0.05 \times 10^{-3} \, \text{M}$. The pH is the negative logarithm of the hydrogen ion concentration, so $\text{pH} = -\log(0.05 \times 10^{-3}) = 3$.

A Solution Is Made by Mixing 0