practicals

Question 1

how to do the distillation of ink and chromotography experiment

Answer 1

-draw a line 2cm from the bottom on the chromotography paper
-a some ink from different pens
-add water to beaker
- place paper in beaker making sure it touches the water
-after some time, measure solvent front
-calculate rF value of each solvent

Question 2

how to prepare copper sulfate crystals

Answer 2

-add 20cm3 of sulfuric acid conical flask
-add that to a water bath
-heat with a bunsen burner
-do not heat it above 50 degrees
-after 3 minutes, remove flask
-add half a spatula of copper oxide to the flask
-mix
-repeat this until there is excess
-filter this
-place this above beaker with water and heat
after 2-3 days, crystals are formed

Question 3

how to do titration

Answer 3

-using pipette, measure out a set volume of the alkali into a flask. then, add a few drops of phenolphthalein or methyl orange
-fill a burette with the known concentration of acid
-slowly add the acid to the alkali and mix
-stop adding when the indicator turns to a neutral color
-record the volume of acid used to neutralise it-titre
-repeat this until you get two concordant results- similar results.

Question 4

how to neutralise acid with calcium hydroxide

Answer 4

-pour the acid into beaker
-place some of the acid in one strip of indicator paper
-record the colour change
-add .3g of calcium hyroxide to the beaker
-mix until it becomes colourless
-check pH again
-add another .3g of calcium hydroxide
-repeat until neutralisation has occured
-add more calcium hydroxide to conform this

Question 5

how to do electrolysis of copper sulphate

Answer 5

-attach copper strips to power supply and ammeter
-measure starting mass of each strip
-fold the strips into a beaker to act as electrodes
-add copper sulfate solution
-adjust the current to 0.2 amps using a variable resistor
-after 20mins, record mass of electrodes
-repeat this with higher currents