PAPER 2 - REQUIRED PRACTICALS

Question 1

1. rate of reaction - aim

Answer 1

investigate the effect of changing temp of the rate of reaction

Question 2

1. rate of reaction - method

Answer 2

1. add 50cm3 of dilute sodium thiosulfate to concal flask
2. put conicle flask on paper w black cross
3. then add 10cm3 of dilute HCl
4. swirl and start timer
5. when you cant see the cross, stop the timer and record time
6. record temp of mixture
7. repeat with different starting temps of sodium thiosulfate

Question 3

1. how to calculate the rate of reaction and graph - results

Answer 3

• 1000/time
• plot on graph
  temp on x
  ror on y

Question 4

1.2. ror production of gas - aim

Answer 4

investigate the effect of changing concentration on the rate of reaction

Question 5

1.2. ror production of gas - method

Answer 5

1. support gas syringe with a stand, boss and clamp
2. add 50cm3 of dilute HCl to conicle flask
3. add 0.4g calcium carbonate to flask
4. connect to gas syringe and start the clock
5. then clean apparatus when reaction complete
6. repeat steps with dif concentrations of HCl

Question 6

1.2. ror production of gas - results - mean ror

Answer 6

total mass of gas produced / time

Question 7

1.2. ror production of gas - how can you tell when the reaction is over

Answer 7

no more gas is being produced and the line on the graph become horizontal

Question 8

2. chromatography - aim

Answer 8

inveestigate how paper chromatogography can be used to seperate and tell the difference between coloured substances

Question 9

2. chromatography - method

Answer 9

1. draw a 2cm pencil line across the bottom of the chomatograph paper
2. use a capillary tube to put a small dot of each sample onto the line on the paper
3. add the solvent to the beaker and place the paper in it
4. wait for solvent to travel up the paper
5. then remove and allow to dry and meaure the distmnaces travelled by solvent and substances
6. calculate Rf value

Question 10

3. identifying ions - fame test method

Answer 10

1. pur small volume of metal solution in test tube
2. dip wire into it
3. hold tip of wire in blue bunsen burner flame
4. observe colour

Question 11

3. identifying ions - metal hydroxide - method

Answer 11

1. add metal ion solution to a test tube
2. add sodium hydroxide in excess
3. observe the precipitate formed
4. use colour to identify metal ion

Question 12

4.1 analysing water samples - aim

Answer 12

analyse samples of water from different sources in terms of pH and the presence of dissolved solids

Question 13

4.1 analysing water samples - method

Answer 13

1. test pH of each water sample given w universal indicator or pH meter and record
2. for each sample pour 50cm3 into a clean pre weighed evaporation basin
3. heat w bunsen burner tripod and gauze until no liquid left
4. allow to cool then weigh evaporating basin agaon and caluclate the mass of the solid that remains in basin

Question 14

4.2 distillation - aim

Answer 14

to distill seawater and obtain potable water

Question 15

4.2 distillation - method

Answer 15

1. set up apparatus
2. heat water until boiling gentle
3. then you should see distilled water being produced