You are Here: Home >< A-levels

# Buffer solution calculation watch

1. 1.00g of potassium ethanoate is dissolved in 50 cm^3 of 0.200 mol dm^-3 ethanoic acid (Ka = 1.74 * 10^-5 mol dm^-3)

Find the pH.

When you work it out could you please show me step by step how you did it, I know how to use Ka calculations but this one gave me an answer of -1.232 for the pH. ????????????????
2. 1) Find the number of mol or potassium ethanoate
2) use the equation, pH = pKa + lg (concentration of salt/ concentration of acid)
- in this case, concentration of salt is the no. Of mol per dm3 of potassium ethanoate
- acid ... just find the no. Of mol (mol = concentration x volume)
3. Correct me if I am wrong! Thanks
Attached Images

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: October 27, 2017
Today on TSR

Get the low down

### University open days

• University of Exeter
Wed, 24 Oct '18
Wed, 24 Oct '18
• Northumbria University
Wed, 24 Oct '18
Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets