A Level Chemistry question - acid base titration pH calulationWatch
20cm3 of methanoic acid (Ka = 1.8x10^-4 moldm^-3) of concentration 0.10 moldm^-3 is titrated against NaOH of concentration 0.05 moldm^-3
Calculate the pH of the solution:
- Initially (I worked this out to be 2.37)
- After 10cm3 of the alkali is added
- After 20cm3 is added
- After 30cm3 is added
- After 50cm3 is added
How do I do this?? I get the first one...
Step 1. Find the number of moles of alkali that are added and the number of moles of acid currently in the solution
2. Take away the smallest from the largest to find the moles of salt formed and the moles of acid left.
3. Find new concentrations of the salt and acid by dividing each by the total volume in dm^3
4. Plug into equation: to find [H+]
5. Find pH by -log[H+]