Practical Techniques

Question 1

What are the types of column chromatography

Answer 1

High performance liquid, gas chromatography. Both separate substances because of different retention times in a column and are used with mass spec things like forensics in sports

Question 2

How to measure molar volume of gas - sources of error

Answer 2

Add together two reactants that release a gas. use a gas syringe or collection over water. Lost as reaction may occur before bung inserted, Gases may be soluble in water so lost

Question 3

Make sure to do what when titrating , and what do we read burette to

Answer 3

Run through with what we are testing so jet space is full, take out funnel, read from bottom of meniscus, swirl indicator to make sure fully mixed each time. READ TO @ DP. 0.00, 0.05.

Question 4

How to calculate uncertainty

Answer 4

Error ( Only plus) / measurement on apparatus.

Question 5

How to test for a sulphate

Answer 5

Barium chloride forms barium sulphate which is white

Question 6

Test for halide ions

Answer 6

Silver nitrate and nitric acid. Then with dilute ammonia soluitojn

Question 7

What indicator do we use for iodine clock reactions

Answer 7

Starch which goes from yellow/brown to blue/black

Question 8

How to prepare a pure organic solid through recstrystalisation

Answer 8

1. Dissolve in minimum of hot solvent
2. Filter through filter paper normally
3. Cool by putting in ice. Cold solvent
4. Suction filter with Buchner flask separates crystals
5. wash with distilled water
6. dry between absorbent paper or in drying oven