Question

question 6
mark as. none
calculate the hydroxide ion concentration for a solution with
$h_3o^+_{eq}=2.8 \times 10^{-5}$ m. use \e\ for scientific notation
respond with the correct number of significant figures in scientific notation (use e notation and only 1 digit before decimal e.g. 2.5e5 for $2.5 \times 10^5$)
type your numeric answer and submit

Explanation:

Step1: Recall water autoionization constant

At 25°C, $K_w = [H_3O^+][OH^-] = 1.0 \times 10^{-14}$

Step2: Rearrange to solve for $[OH^-]$

$[OH^-] = \frac{K_w}{[H_3O^+]}$

Step3: Substitute given values

$[OH^-] = \frac{1.0 \times 10^{-14}}{2.8 \times 10^{-5}}$

Step4: Calculate and format result

$[OH^-] = 3.6 \times 10^{-10} = 3.6\text{E-10}$

Answer:

3.6E-10