Question

1. List three important products which are colloids. 16 pts latin C NaCi 2. Photographic film is AgBr in a gelatin layer. From the results obtained here, what is the purpose of the gelatin in films? 5 pts to protect the Film 3. Raw egg white is a colloidal suspension of proteins in water. What changes occur when an egg is cooked? Explain! 4 pts

Answer 1

Answer 1 Colloids are heterogeneous solution with properties like do not separate on standing, does not get separated by filtration, scatter light (show Tindal effect), translucent etc. The three important products which are colloid are: • Milk • Paints • Whipped cream Answer 2 The gelatin is used on the films to evenly spread the photographic film and it being a colloid allows the light to pass. Thus, we can clearly see the image. Answer 3 Raw egg is a colloid of protein in water. When temperature increased, the denaturation of protein occurs. Denaturation is the process in which protein, the bonds holding the protein are broken down by the action of heat, acid etc. When egg is cooked, the intermolecular forces holding the protein are broken down. It is an irreversible process as you cannot get the raw egg back once it is cooked.