What volume of coffee (pH =5.0) would be required to have .25 moles of H3O+ ions? (Hint: two step)
0.25M H3O^+/(10^-5)mol H3O^+/Liter = 25,000 Liters (one step)
To calculate the volume of coffee required to have a specific number of moles of H3O+ ions, we need to follow these two steps:
Step 1: Calculate the concentration of H3O+ in the coffee
Step 2: Use the concentration to find the volume of coffee needed to obtain the desired number of moles of H3O+ ions.
Step 1: Calculate the concentration of H3O+ in the coffee
Given that the pH of coffee is 5.0, we can determine the concentration of H3O+ ions using the equation: pH = -log[H3O+].
Rearranging the equation, we have: [H3O+] = 10^(-pH).
Substitute the pH value into the equation:
[H3O+] = 10^(-5.0) = 1 x 10^(-5) M.
Step 2: Calculate the volume of coffee required to have the desired moles of H3O+ ions
We can use the formula: moles = concentration x volume (in liters).
Rearranging the equation, we have: volume = moles / concentration.
Substitute the given values into the equation:
volume = 0.25 moles / (1 x 10^(-5) M).
Simplifying the expression, we have:
volume = 0.25 / (1 x 10^(-5)) L.
Finally, performing the calculation, we get:
volume = 25,000 liters.
Therefore, 25,000 liters of coffee with a pH of 5.0 would be required to have 0.25 moles of H3O+ ions.