Notes

1. identify Mg,Cu, Zn, Pb, Sn, Al - how they look like, the colour, the texture

DCPIP EXPERIMENT
1. Put 1 ml of DCPIP solution into specimen tube using a 1 ml
syringe needle
2. Fill the 5ml syringe needle with ascorbic acid. Ensure there is no
air bubbles trapped in it
3. Insert the tip of the 5ml syringe needle into the DCPIP solution
and slowly drip the ascorbic acid drop by drop until solution of
DCPIP turns colourless. Make sure that the tip of the 5 ml
syringe needle remains in the DCPIP solution.
4. Volume of ascorbic acid needed to decolourise the DCPIP solution is
recorded
5. Step 1 to 5 is repeated using orange juice, lime juice and pineapple juice

PRECAUTIONARY STEP
make sure that the fruit juice are prepared fresh because the content of vitamin C in the fruit juice wil be destroyed once exposed to atmospheric oxygen

b)(i) Type of fruit juice
(ii) volume of fruit juice needed to decolourise 1ml of DCPIP
solution
(iii) volume of DCPIP solution

c) the higher the volume of fruit juice needed to decolourise the DCPIP solution, the higher the concentration of vitamin C

e) Concentration of vitamin C is the content of vitamins contained in a fruit juice. This is shown by volume of fruit juice needed to decolourise the DCPIP solution. It is affected by different type fruit juice

f) the volume of orange juice needed to dilute the colour of DCPIP solution is higher. This is because the vitamin C in orange juice is oxidised