a solution of ammonia has a ph of 11.8. what is the concentration of oh⁻ ions in the solution? useful…

a solution of ammonia has a ph of 11.8. what is the concentration of oh⁻ ions in the solution? useful formulas include h₃o⁺=10⁻ph, oh⁻=10⁻poh, ph + poh = 14, and h₃o⁺oh⁻=10⁻¹⁴. 1.58×10⁻¹² m 6.31×10⁻³ m 2.20 m 158 m

a solution of ammonia has a ph of 11.8. what is the concentration of oh⁻ ions in the solution? useful formulas include h₃o⁺=10⁻ph, oh⁻=10⁻poh, ph + poh = 14, and h₃o⁺oh⁻=10⁻¹⁴. 1.58×10⁻¹² m 6.31×10⁻³ m 2.20 m 158 m

Answer

Answer:

B. $6.31\times 10^{-3}\text{ M}$

Explanation:

Step1: Calculate pOH

Given $\text{pH}+\text{pOH}=14$, and $\text{pH} = 11.8$. So $\text{pOH}=14 - \text{pH}=14 - 11.8 = 2.2$.

Step2: Calculate $[\text{OH}^-]$

Since $[\text{OH}^-]=10^{-\text{pOH}}$, substituting $\text{pOH}=2.2$ into the formula, we get $[\text{OH}^-]=10^{- 2.2}\approx6.31\times 10^{-3}\text{ M}$.