In my investigation I plan to find out how much vitamin C there is in orange juice, pineapple juice and tropical juice and then compare my results to find out which juice has the most vitamin C. The independent variable is the type of juice and the dependant variable is the volume of fruit juice needed to decolourise 1cm3 Of 1% DCPIP solution.
DCPIP solution can be used to measure the amount of vitamin C in each juice as an antioxidant (like vitamin c) reduces the blue dye, DCPIP changing it from blur to colourless.
Method
1) Pipette 1cm3 Of 1% DCPIP solution into a test tube 2) Fill a burette with the 1% vitamin C solution and position it above the test tube with DCPIP, allowing the vitamin C solution to decolourise the blue DCPIP drop by drop, shaking the test tube gently. Record the exact amount of vitamin C solution needed to decolourise the DCPIP. Repeat the procedure three times and then average the results. 3) Repeat the procedure using the fruit juices instead of the 1% Vitamin C solution. 4) Calculate the mass of vitamin C that is required to decolourise 1cm3 of 1% DCPIP solution (multiply the amount of vitamin C solution needed to decolourise the DCPIP in cm3 by 10 as there’s 10mg of vitamin C in 1cm3 of 1% vitamin C solution) 5) Present finding in a table, stating which fruit juice provided the most vitamin C
Diagram
Control variables * Volume of DCPIP * Concentration of DCPIP * Type/shape of test tubes
Risk assessment Hazard | risk | Level of risk | Emergency measures | prevention | Glass test tubes breaking | Injury from getting cut by glass | Medium | Seek medical attentionAnd Use bandages | Use test tube racks Keep test tubes away from the edge of the table to prevent them from falling over. | Allergic reaction to juices/DCPIP | A rash or another sign of an allergic reaction | small | Seek medical attention | Avoid contact with the