Blog Eight

Today, I made modifications to my experimental report. I wanted to do so before I actually conducted my trials. Reflecting on the feedback of my draft experimental design, I had been recommended to change my hypothesis, add a few more details to my method and make my variables more precisely controlled. I read through my SRP Booklet carefully and this assisted me with making changes to my report, giving me examples of experimental designs. Having changed my procedure meant that I had to include or take away certain equipment. I have recorded my changes below.

Hypothesis: The quantity (amount) of Cocoa Butter present within the Chocolate, will affect the chocolate’s melting speed.

Variables
Independent Variable: My Independent Variable is the type of chocolate that I will be using; milk, dark and white.
Dependant Variable: My Dependant Variable is measuring how long it takes for each different type of chocolate to melt completely.
Controlled Variable: My Controlled Variables include the brand of Chocolate that is being used (Cadbury), the serving size of the chocolate; 25g per square, the amount of chocolate being used for each trial, and the temperature of the water used in melting the chocolate (boiling point 100°C).

 Equipment List:

·         Regular Sauce Pan                                           

·         Regular Stainless Steel Bowl

·         Cadbury 25g White, Milk, Dark Chocolate Blocks

·         Stopwatch with 0.1 Second Accuracy

·         500mL Cold Tap Water per trial

·         Measuring Cylinder 500mL

·         Digital Scale

·         Regular Kitchen Knife

·         Wooden Chopping Board

·         Metal Spoon

 Experimental Procedure (Method)

1)     Fill up a measuring cylinder with 500mL of cold tap water.

2)     Pour this water, into a regular saucepan and place it over the stove at a medium heat.  

3)    Whilst the water is heating, cut a row of chocolate from the three Cadbury blocks using a kitchen knife and a wooden chopping board. This should be 4 squares with 25g/square (according to the nutrition panels).

4)     To ensure accuracy and consistency, place one of the broken rows of chocolate on a digital scale, using ‘Grams’ as the unit of measurement. The measurement that is recorded will be the initial weight used for all trails.   

5)     Once the water has boiled, you will know when it has started boiling because bubbles will slowly rise to the surface of the water; place one of the chocolate types into a regular stainless steel bowl.     

6)      Then, have this put on top of the saucepan filled with the boiling water.

7)     With the timer, start timing how long it takes for the chocolate to melt completely once the bowl is placed in the saucepan. Make sure to keep the stove running on the medium heat.

8)     Every 10 seconds, lightly press down on the chocolate 5 times using your metal spoon. Do this until the chocolate has melted entirely. If the chocolate is left as is, it will take extremely long for the particles to physically separate. Putting slight pressure on the chocolate with the spoon will visibly show you that the chocolate begins to melt automatically, once placed over the heat.  

9)    Record the result of how long it takes for all of the chocolate to melt, and stop timing when the chocolate has completely melted.

10) Repeat this for the other two different types of chocolates, within the trail; however keep the water boiling, as you rinse your bowl and wash your spoon.

11) When, you have completed one trail, repeat the same process, changing the boiling water which would be close to evaporation, at the start of each trail

12)  Also, remember to have at least 5 trials for each chocolate.