Question

select the correct answer.
the ph scale measures the acidity of a liquid as a function of its hydrogen ion concentration.
$\text{ph} = -\log \text{h}^+$
a chemist needs to prepare a solution with a ph of 3. what $\text{h}^+$ concentration should the solution have?
a. 1,000
b. 0.001
c. 100
d. 0.01

Explanation:

Step1: Substitute pH into formula

Given $\text{pH} = 3$, substitute into $\text{pH} = -\log[\text{H}^+]$:
$3 = -\log[\text{H}^+]$

Step2: Rearrange to isolate log term

Multiply both sides by -1:
$\log[\text{H}^+] = -3$

Step3: Convert log to exponential form

Since $\log(x)=y$ means $10^y=x$:
$[\text{H}^+] = 10^{-3}$

Step4: Calculate the value

$10^{-3} = \frac{1}{10^3} = 0.001$

Answer:

B. 0.001