1)bleaching of flowers by chlorine is permanent. while bu so2 its temporary.. explain.
2)all the bonds in pcl5 are not equivalent.. explain..
3)sulphur has greater tendency for catenation than oxygen.. explain
4)Zr and Hf have identical size.. explain
5)the lowest oxidation state of manganese is basic.. while the higest is acidic.. explain..
6)name one substance which acts as both.. (analgesic and antipyretic..)
Due to paucity of time it would not be possible for us to provide the answers to all your queries. We are providing solutions to some your good queries. Try solving rest of the questions yourself and if you face any difficulty then do get back to us.
1. Both sulphur dioxide and chlorine are bleaching agents. Both require moisture for their action as a bleaching agent. However, the bleaching action of chlorine is based on oxidation, while that of sulphur dioxide is based on reduction. Also, while bleaching by sulphur dioxide is temporary in nature, chlorine causes permanent bleaching.
When chlorine reacts with water, it produces nascent oxygen. This nascent oxygen then combines with the coloured substances present in the organic matter to oxide them into colourless substances.
Coloured substances + [O] → Oxidized colourless substance
On the other hand, sulphur dioxide actions as a bleaching agent by reduction. It removes oxygen from the dye. However, the atmospheric oxygen slowly reoxides the bleached material, because of which the material changes back to its original colour. This is why bleaching by sulphur dioxide is not permanent.
3. Sulphur exhibits tendency to catenation. The enhanced tendency of catenation in S is due to fairly large bond energy of the S-S bond.
O—O 142 kJ/mol S–S 268 kJ/mol O=O 499 kJ/mol S=S 352 kJ/mol
This means that O=O is stronger than S=S, while O–O is weaker than S–S. So, in sulfur, single bonds are favoured and catenation is easier than in oxygen compounds.
It seems that the reason for the weaker S=S double bonds has its roots in the size of the atom: it's harder for the two atoms to come at a small enough distance, so that the p-orbitals overlap is small and the π bond is weak.
6. Aspirin (Acetyl salicylic acid) is a chemical substance which lowers body temperature and reduces pain as well. Therefore it acts both as analgesic and antipyretic.