Chemistry Acid/Base Titration Question help?!?
6) what is ph of solution after 25 mL of 0..1 M NaOH is titrated with 30 mL of 0.1 M HCL
Please show working out!
A friend told me it's e but I don't know how she did it
- ChemTeamLv 78 months ago
We know that NaOH and HCl react in a 1:1 molar ratio.
We know that the molarities are equal.
Therefore, equal volumes will neutralize each other exactly.
That accounts for 25 mL. What about the left over 5 mL of HCl solution?
Compute the new molarity:
M1V1 = M2V2
(0.1) (5) + (M2) (55)
M2 = 0.009090909090909 M
Now, calculate the pH (knowing that HCl is a strong acid):
pH = -log 0.009090909090909
pH = 2.04
answer choice a
If the molarities were different, we would have to calculate the moles of each reactant (rather than using molarities directly). We would then the amount of left over moles, calculate a new molarity (using moles divided by liters of solution) and then calculate a pH.