3.3 - Titration and mole calculations

Question 1

How to convert mass into moles

Answer 1

Moles of atoms = mass \ mr

Question 2

How to convert moles into mass?

Answer 2

Moles x mr = mass

Question 3

How to get from mol dm-3 to gdm-3

Answer 3

Mol to gm = X MR

Gm to mol = \ MR

Question 4

What’s the equation linking moles and concentration?

Answer 4

Moles = concentration x volume (cm3) / 1000

Question 5

What can be used to accurately measure solutions that go into a conical flask?

Answer 5

A volumetric pipette

Question 6

What is the mole equivalent to?

Answer 6

An elements mass number

Question 7

Describe how you could make crystals of sodium chloride from sodium hydroxide and hydrochloric acid using titration method

Answer 7

1. Measure 20cm3 of sodium hydroxide and put it into a conical flask and add indicator
2. Add the acid from a burette recording the starting volume
3. Near the end point when the colour has nearly changed, add the acid drop-wise until the colour just changes
4. Record final volume and calculate the volume of the acid added
5. Repeat without indicator adding the same volume of acid
6. Bring the salt solution to the boil in an evaporating basin to remove some of the water
7. Turn bunsen off and leave solution to evaporate to form dry crystals