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Wednesday, February 12, 2020

What are the Silicones? Give one example one cyclic Silicone?

Silicones are organosilicon polymeric compounds containing repeated R2SiO units and (-Si-O-Si-) linkage.The name is given silicone because their empirical formula is analogous to that of ketones (R2CO). Silicones may have the cyclic structure also having 3, 4, 5 and 6 nos. of silicon atoms within the ring. Alcohol analogue of silicon is known as silanol.


What is "calgon" ? Give structure and its uses?

Hexamer of meta phosphoric acid exist as sodium salt which is called  sodium metaphophate or sodium polymetaphosphate and it is commercially  known as "CALGON" and use as water softener.



Related Questions:


Why bond angle of hydrides of group 15, decreases down the group?

Hydride: NH3 > PH3 > AsH3 >SbH3
H-M-H angle: 107 > 92 > 90 > 91 (Degree)
This is due to the decrease in electronegativity of the central atom of hydride. As the electronegativity decrease the electrons which were more close to central atom at lower hydrides tends to more far from it and bp-bp repulsion decreases.

Related Questions:

Which is more basic N(CH3)3 or N(SiH3)3 , explain?

Why liquification of noble gases is quite difficult?

liquification of noble gases is quite difficult.It is due to the fact that there are only weak vander waal's forces which hold atoms together, but due to increase in these forces down the group the ease for liquification increases down the group.

Tuesday, February 11, 2020

What are "pyro" oxy acids?

The term "Pyro" use for those oxy acid which are formed by removal of one water molecule from two molecules of same oxy acid and resulting product is also an oxy acid then the product acid is named with prefix "Pyro"
For Examples:
H3BO3 (), H2CO3 (), H4SiO4 (), HNO3 (×), HPO3 (), HPO4 (), H2SO4 (), HCl4 (×)
(×) "Pyro" form not possible.
() "Pyro" form possible.
(1) In general those oxy acids are formed “pyro” acid which contains atleast two hydrogen atoms.

(2) In general all the “pyro” oxy acids contain oxy-linkage except "Pyro sulphurous acid"
            What are "Ortho" or "Meta" oxyacids?