LB: Trial 1 Procedure

LB: Trial 1 Procedure 

Research Question: Does the process of gelatinisation cause the GBR to float?
Hypothesis: The higher the surface area to volume ratio, the faster the GBR floats in water.

Steps

   1. Measure out 100g of rice flour and water using a weighing scale, mix until evenly distributed.

Dough after mixing

   2.  Divide the dough into 6 parts, 4 parts of 40g each using the scale and 2 parts of 20g each using a spring balance.

Use cling wrap to prevent the dough from sticking

Keep adding dough, then press the lumps together when the amount is correct

3.  Roll all parts into balls. Then, evenly flatten 2 of the 40g balls until about 1 cm thick, leaving the rest untouched.

4.  Mark 1 GRB from each category (40g flats, 40 balls and 20g balls) with a dot of green dye. 
5. Lay all GRB on black paper covered with plastic, with a ruler in sight, and then take a photo from directly above.

This photo will be used for measuring surface area 

6. Individually wrap the 2 20g balls in cling wrap and place them inside a plastic bag. Squeeze out remaining air before twisting the bag closed.

Due to the cling wrap, the balls will not stick together

7. Fill a displacement can with water, and slowly submerge the plastic bag while using the 100ml measuring cylinder to catch the displaced water. Record the volume and repeat steps 6-7 for the other two pairs.

Place the can on a flat elevated surface, e.g. kitchen sink

    8. Using a 250ml cylinder, pour 750ml of water  into a pot. Put the pot on a hotplate set to 200°C and start the stopwatch. When the water has begun to boil, slowly lower all GRB into the water with a strainer.

The water should take about 3 minutes to boil

Make sure the GRB are not sticking together

      9. Stir continuously with the strainer and record the time it took for each GRB to float. Turn off the hotplate when all GRBs are floating.

The white 20g ball floated first.

    10. Using the strainer, transfer all GRB into a plate while making sure they are not touching each other (prone to sticking) and leave them to cool for 30 minutes.

11. Repeat step 5. 

12. Repeat steps 6-7, but directly slipping the GRBs into the displacement can without wrapping them. 

13. Weigh each GRB with the spring balance again.