Question

what is the ph of a 1 × 10⁻⁴ mol hcl solution? (1 point)

o 6
o 8
o 2
o 4

Explanation:

Step1: Recall pH formula

The formula for pH is $pH = -\log[H^+]$.

Step2: Determine $[H^+]$ concentration

HCl is a strong - acid and completely dissociates in water. For a $1\times10^{-4}\ mol/L$ HCl solution, $[H^+]=1\times10^{-4}\ mol/L$.

Step3: Calculate pH

Substitute $[H^+]=1\times10^{-4}$ into the pH formula: $pH = -\log(1\times10^{-4})$. Since $\log(1\times10^{-4})=- 4$, then $pH = -(-4)=4$.

Answer:

D. 4