Explain the cleansing action of soaps.
Cleansing action of soaps : Soaps contain two parts, a large hydrocarbon which is a hydrophobic (water repelling) and a negative charged head, which is hydrophillic (water attracting). In solution water molecules being polar in nature, surround the ions & not the organic part of the molecule. When a soap is dissolved in water the molecules gather together as clusters, called micelles. The tails stick inwards & the head outwards. The hydrocarbon tail attaches itself to oily dirt. When water is agitated, the oily dirt tends to lift off from the dirty surface & dissociates into fragments. The solution now contains small globules of oil surrounded detergent molecules. The negatively charged heads present in water prevent the small globules from coming together and form aggregates. Thus the oily dirt is removed from the object.
Compounds with antiseptic properties are
(a) CHCl, (b) CHI3
(c) Boric acid (d) 0.3 ppm aqueous solution of Cl2
Assertion (A): Chemical messengers are chemicals that enable communi ¬cation of message between two neutrons or between neurons and muscles. Reason (R): Chemicals enter the cell through receptor.
Sodium salts of some acids are Very useful as food preservatives. Suggest a few such acids.
Which of the following compounds are administered as ant-acids?
(a) Sodium carbonate (b)Sodium Hydrogen carbonate
(c)Aluminium carbonate (d)Magnism Hydroxide
How does the branching of hydrocarbon chain of synthetic detergents affect their biodegradability?
What is the advantage of using antihistamines over antacids in the treatment of acidity?
Write the chemical equation for preparing sodium soap from glyceryl oleate and glyceryl palmitate. Structures of these compounds are given below:
(i)(C15H31COO)3C3H5-Glyceryl palmitate
(ii)(C17H32COO)3C3H5-Glyceryl oleate
Which of the following are not used as food preservatives?
(a) Table salt (b) Sodium hydrogen carbonate
(c) Cane sugar (d) Benzoic acid
With the help of an example explain how do tranquilizers control the feeling of depression?
What happens when the bond formed between an enzyme and an inhibitor is a strong covalent bond?
Match the class of compounds given in Column I with their functions given in Column II.
Assertion (A): Chemical messenger gives message to the cell without entering the cell.
Reason (R): Chemical messenger is received at the binding site of receptor proteins.
In what respect do prontosil and Salvarsan resemble? Is there any resemblance between azo dye and prontosil? Explain.
Aspirin is pain relieving antipyretic drug but can be used to prevent heart attack. Explain.
Which of the following statements are incorrect about receptor proteins?
(a) Majority of receptor proteins are embedded in the cell membranes.
(b) The active site of receptor proteins opens on the inside region of the cell.
(c) Chemical messengers are received at the binding sites of receptor proteins.
(d) Shape of receptor does not change during attachment of messenger.
Which of the following are sulpha drugs?
(a) Sulphapyridine (b) Prontosil
(c) Salvarsan (d) Nardil
If soap has high alkali content it’irritates skin. How can the amount of excess alkali be determined? What can be the source of excess alkali?
Between sodium hydrogen carbonate and magnesium hydroxide which is a better antacid and why?
Assertion (A): Sulpha drug contain sulphonamide group.
Reason (R): Salvarsan is a sulpha drug.
