Experiment: DCPIP and Vitamin C

A week after doing the 'energy value' experiment, the Form Four Helpilians again doing another experiment : Determine the vitamin C content in different type of fruit juices..

Of course it would be better if they could use all the fresh fruits to extract the juices....but it will be a bit messy doing that in the Lab...so I decided that they could have just used the fruit juices on shelves..

...It was not so much of the result of the experiment which concerned me...but.... the procedure of doing the experiment !!

Since this experiment has been asked once in SPM examination for Question 1, Paper 3, I have reminded the girls to take note of the way to write a proper 'planning & designing' of this experiment, which probably might be asked in paper 3 BUT instead for Question 2.

It starts with AIM : To determine the content/percentage of Vitamin C in a different fruit juices.

PROBLEM STATEMENT : What is the content of vitamin C in different fruit juices ?

HYPOTHESIS: Orange juice has a higher content of vitamin C than blackcurrent juice. //any reasonable sentence

VARIABLES:

Manipulated : Types of fruit juices

Responding : volumes of fruit juice used to decolourise (blue) DCPIP solution.//percentage of Vitamin C//vitamin C concentration

Constant : Volume of DCPIP (10ml)

APPARATUS & MATERIALS :

(Dont forget : Syringe with needle and 0.1%Ascorbic acid ! )

TECHNIQUE: measure and record the volume of fruit juices needed to decolorise DCPIP solution using scaled syringe.// calculating the content of vitamin C by using the Formula :.........

PROCEDURE;

**Draw apparatus

Dont forget the precaution !!

RESULT: A TAble !

CONCLUSION: Repeat hypothesis sentence .

**Dont forget discussion (If it is a PEKA Report )

Your TASK:

Write a full complete report as if you are answering for Paper 3 Question 2..You may scan it, attach, and mail it to me : at mahadiah@gmail.com so that I can mark it for you...