Required practicals

Question 1

Purification of water samples from different sources method

Answer 1

1)pH indicator to analyse pH of sample
2)set up water in a conical flaskover a Bunsen burner with thermometer in it and a condenser weigh water in and out pouring into glass of distillate (pure)
3)heat seat volume to 100 degrees so liquid—->gas
4)water collects in condenser changes from gas ——>liquid
Collect pure water in beaker
5)when all water from sample evaporated measure mass of solid that remains to find the amount of dissolved solids present in sample

Question 2

Part2 hazards and risks

Answer 2

Risk of burning themselves on equipment

Question 3

Determination of reacting volumes of solutions of a strong acid and a strong alkali by titration method

Answer 3

1)wash and rinse Pipette with the alkali being used
2)use pipette to measure out a known accurate volume of the alkali
3)place alkali in a clean dry conical flask
4)add suitable indicator(phenolphthalein)
5)place flask on white tile so colour can be seen clearly
6)place acid in burette that has been washed and rinsed with the acid
7)take reading of volume of acid in burette
8)carefully add acid to alkali ,swirling flask to thoroughly mix
9)continue until indicator changes colour
End point\
10)take a reading of volume of acid in burette (final reading)
11) calculate volume of acid added by initial reading-final reading

Question 4

Part2 hazards and risks

Answer 4

Acids and alkalis could harm skin or eyes so protection must be worn

Question 5

Preparation of a pure,dry sample of soluble salt from and insoluble oxide or carbonate method

Answer 5

1) add metal oxide or carbonate to a warm solution of acid till no more will react
2)filter excess metal oxide or carbonate to leave a solution of salt
3) gently warm salt solution so that water evaporates and crystals of salt are formed

Question 6

Part2 hazards and risks

Answer 6

1) acid can cause damage to eyes protection must be worn
2)hot equipment causes burns so care must be taken

Question 7

Investigate what happens when aqueous solutions are electrolysed by using inert electrodes

Answer 7

1)set up equipment beaker with aqueous solution in it with leads with inert(unreactuve)electrodes on
2)pass an electric current through the aqueous solution
3)observe the products formed at each electrode

Question 8

Part2 hazards and risks

Answer 8

1) low volatile to prevent electrocution
2)room well ventilated and experiment for short period of time as exposure to gas

Question 9

Investigate the variables that affect temperature changes in reacting solutions method

Answer 9

1) set up equipment polystyrene cup filled with hydrochlauric acid and add metal powdered with a thermometer in cup whilst all in a Pyrex beaker
2) take temp of acid
3)add metal powder and stir
4)record highest temp the reaction mixture reaches
5)calculate temp change
6)repeat using a different metal

Question 10

Part2 hazards and risks

Answer 10

Acid damaging eye so wear protection

Question 11

Variables

Answer 11

Independent- metal used
Dependant-temp change
Control-type,concentration and volume of acid