A solution of ethanoic acid is made by dissolving 3g of pure liquid propanoic acid in 500cm^3 water. Given the pH of the solution is 2.98, calculate Ka.

Before using numbers from the question: 1)What is pH? pH = -log[H+] Square brackets mean concentration of H+ so we need to convert given pH to [H+] in the weak acid coefficient 2) To find the concentration we use the formula triangle to get concentration of acid = moles / volume 3) To find moles we use the mass of pure acid used SOLVE: moles of acid = 3/(36+6=32) = 0.0405 moles concentration = 0.0405/0.5 = 0.81 moles dm -3 Ka = [H+]2 / [HA] = (10-2.98) / 0.081 = 1.349 x 10-5

SH
Answered by Sofia H. Chemistry tutor

3171 Views

See similar Chemistry A Level tutors

Related Chemistry A Level answers

All answers ▸

20cm3 of 0.5moldm-3 of HCL is diluted by adding 15cm3 of water. This diluted solution is titrated against a 0.3moldm-3 solution of NaOH. What is the volume of the NaOH in cm3 required to reach the endpoint of the titration?


Calculate the concentration, in mol dm-3, of a solution of chloric (I) acid, HOCl , which has a pH of 4.23. Chloric acid is a weak acid, with Ka = 3.72 x 10^-8


Why is phenylamine a weaker base than ethylamine?


Describe and explain the difference in base strength between ammonia, primary aliphatic and primary aromatic amines.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning