Gelatin is a soluble protein that can be added to different food products - Scottish Highers Chemistry - Question 8 - 2019

The weakest van der Waals’ force between water and gelatin molecules is London dispersion forces.

1. Dissolve the Gelatin: Begin by dissolving the 2 g of gelatin in a small volume of distilled water. This allows for better mixing.

2. Transfer Quantitatively: Next, transfer the gelatin solution quantitatively to a volumetric flask. Rinse the original container with distilled water and add this to the flask to ensure all gelatin is transferred.

3. Fill to the Mark: Carefully fill the volumetric flask with distilled water up to the mark/line, ensuring an accurate 2% solution.

Based on the trend in the data, we can predict that the viscosity for a 10.0% gelatin solution will be approximately 11-12 units.

The rate of hydrolysis is reduced when the pineapple is cooked because heat causes bromelain (the enzyme) to denature. Denaturation changes the shape of the enzyme, which is crucial for its activity. When the enzyme's structure is altered, it cannot effectively bind to and hydrolyze the gelatin molecules.

To provide 500 mg of bromelain, consider the average content of bromelain per gram of pineapple. If we take an average of 21 mg/g, the mass of pineapple needed can be calculated as follows:

egin{align*} ext{Mass of pineapple} &= rac{500 ext{ mg}}{21 ext{ mg/g}} \ & ightarrow ext{Mass of pineapple} ext{ (in g)} = rac{500}{21} \ & ightarrow ext{Mass of pineapple} ext{ (in g)} ext{ approximately } 23.81 ext{ g.} ext{Therefore, about 23.81 g of pineapple is needed to provide 500 mg of bromelain.} \ ext{Note: This is an approximation and may vary within the 13-29 mg/g range.} ext{Final answer: } 23.81 ext{ g}