Calculate the [OH-] concentration if the pOH is 2.55. a) 2.55 M b) 11.45 M c) 3.55 x 10^-12 M d) 2.82 x 10^-3 M
Chemistry · High School · Thu Feb 04 2021
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Answer: To calculate the hydroxide ion concentration ([OH⁻]) from the pOH, you can use the following relationship:
\[ \text{pOH} = -\log[\text{OH⁻}] \]
In this case, you have:
\[ \text{pOH} = 2.55 \]
To find the [OH⁻], we need to reverse the operation represented by taking the negative logarithm. The inverse operation is finding the antilog (10 raised to the power of the negative pOH value):
\[ [\text{OH⁻}] = 10^{-\text{pOH}} \]
\[ [\text{OH⁻}] = 10^{-2.55} \]
To calculate this, you can use a scientific calculator. The exponential expression 10^(-2.55) refers to the number 10 raised to the power of negative 2.55. When you calculate this value, you get:
\[ [\text{OH⁻}] = 2.82 \times 10^{-3} \text{M} \]
So the answer is: d) 2.82 x 10^-3 M