Pre-Assignment

1. Is gel a liquid-solid, solid-gas or liquid-gas system of colloids?
2. In colloidal gel system, which one – the dispersion medium or the dispersed medium – is more by volume and weight?
3. Why is gel-colloid called a pseudo solid mass?
4. What contributes towards the hardness and stickiness of a gel?
5. Is gel a liquid-solid, solid-gas or liquid-gas system of colloids?
6. What is the size of the interstitial pockets of the agar-agar network structure?
7. What happens to the network mesh size on increasing the concentration of agar?
8. "Edible jelly has approximately the density of water." Justify.

Post-Assignment

1. Can one use buffer solution of any pH for the preparation of agar gel?
2. How will the gel property change if the concentration of buffer solution is increased?
3. Why should one remove the flask from microwave at regular intervals and swirl it gently?
4. How can one avoid bubble formation in the gel matrix?
5. What are the temperatures of gelation and gel melting?