Calculate the pH of each solution given the following:

f. [OH⁻] ...

Question

Calculate the pH of each solution given the following:

f. [OH⁻] = 8.2 x 10⁻⁴ M

Accepted Answer

Hey, everyone. We're asked to provide the P H of the solution. If the concentration of hydroxide ions which has a formula of O H minus in the solution is 6.7 times 10 to the negative seven molar. Now to calculate for our P H, we need to recall that the formula is P H is equal to the negative log of the concentration of our hydro num ions which has a formula of H plus. As we can see right here. The questions then provided us the concentration of hydroxide ions and not the concentration of hydrogen ions. So in order to solve for our P H, we need to calculate the concentration of hydro num ions by rearranging our water dissociation expression, which is our K W is equal to the concentration of our hydro num ions times the concentration of our hydroxide ions. Solving for the concentration of our hydro num ions, we can rearrange this expression to be K W divided by the concentration of our hydroxide ions. So plugging in these values, we know that our K W is equivalent to 1.0 times 10 to the negative 14 and we can go ahead and divide this by the concentration of hydroxide ions which is 6.7 times 10 to the negative seven molar. Now, when we calculate this out, we end up with a value of 1.5 times 10 to the negative a molar which is going to be the concentration of our hydro ions. Now that we have the concentration of our hydro ions, we can go ahead and solve for our P H. So plugging in that value, we get the P H is equal to the negative log of 1.5 times 10 to the negative A molar. So when we calculate this out, we end up with a P H of 7.82, which is going to be our final answer. Now, the reason why we have two decimal places in our P H is because we have two significant figures in our concentration. Now, I hope this made sense and let us know if you have any questions.

Calculate the pH of each solution given the following: f. [OH⁻] = 8.2 x 10⁻⁴ M

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