If the H3O+ concentration is 10−7 M, what is
the pH?
pH = -log(H3O^+)
Can you punch that into your calculator?
To calculate the pH, we can use the formula:
pH = -log[H3O+]
Given that the H3O+ concentration is 10^-7 M, we can plug in this value into the formula:
pH = -log(10^-7)
To simplify the logarithm, we can use the fact that log(1/x) = -log(x):
pH = -(-7) log(10)
Now we can apply the logarithmic property log(a^b) = b * log(a):
pH = 7 * log(10)
Using a calculator or logarithmic table, we can find that log(10) = 1:
pH = 7 * 1
Therefore, the pH is equal to 7.
To find the pH from the H3O+ concentration, you can use the following formula:
pH = -log[H3O+]
In this case, the H3O+ concentration is given as 10^(-7) M. So, substituting this value into the formula:
pH = -log(10^(-7))
To evaluate this expression, we first need to evaluate the exponent:
10^(-7) = 1/(10^(7)) = 1/10,000,000 = 0.0000001
Next, take the negative logarithm (base 10) of this value:
pH = -log(0.0000001)
The logarithm of 0.0000001 is -7. Therefore, the pH is 7.