Chemistry required practicals

Question 1

How to make salts

Paper1

Answer 1

1 – as an excess amount of copper oxide to 20 cm³ of sulphuric acid And then stir
2-Wait till the reaction stops and then use filtration to remove the unreacted copper oxide
3-Evaporate and the solution in an evaporating dish Over the Bunsen burner until your left of copper sulphate crystals

Question 2

Required practical investigating temperature change and energy transfer

(Paper1)

Answer 2

1-Put 25 cm³ of 0.25 mol/dm3 of hydrochloric acid And sodium hydroxide in different beakers
2-Please the bakers in a water bath set to 25° until they’re both the same temperature
3-Had the hydrochloric acid and sodium hydroxide to a polystyrene cup with a lid
4-You can add cotton wall to prevent energy transfer
5-Take the temperature of the mixture every 30 seconds and record the highest temp
6-Repeat the steps up to 4 times using different concentrations of hydrochloric acid

Question 3

Rate of reaction experiments-Investigating how changes in concentration affect the rate of reaction – cross method

(Paper two)

Answer 3

One – add a set volume of die loot sodium thiosulphate to a conical flask
To – place a flask on top of a piece of paper with a cross on it and add some die loot hydrochloric acid and start the stopwatch
Three – measure the time it takes for the cross to disappear as the cloud the sulphur participate is formed
Four – repeat with different concentrations however the amount of liquid and acid mastering the same
Five – this shows the effect of increasing concentration – the higher the concentration the quicker the reaction takes

Question 4

Over action experiment – effective concentration – gas production

(Paper two)

Answer 4

Measure 50 cm³ of one mole of hydrochloric acid and added to a conical flask
– 3 cm of a piece of magnesium ribbon And places stopper on the conical flask
– record volume Hydrogen gas produced every 10 seconds for three minutes
– repeat experiment for 2 moles

Question 5

Chromatography

Paper two

Answer 5

1–2 horizontal line across the paper near the bottom
To – place a dot of each colour on the line using a capillary tube
Three – place the paper and in the beaker so that the bottom of the paper sits in the water
Four – measure the distance moved by the solvent and the distance moved by each colour. Measure the starting line to the centre of the colour. Calculate the RF value for each colour