1all lanthanides are non radioactive except promethium
i don kno whether dis s in jee syllabus .. jus wanted to post it.........
I am starting this thread where there will be all the exceptions in chemistry....
plz post here... the exceptions in chemistry u know....grow it up...it may b helpful...
i m starting with a simple one.......
AgCN is a sparingly soluble salt that display increase in solubility in presence of KCN(common ion)
this is due to fomation of water soluble complex salt K[AgCN)2]
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15 Answers
1well a simple one.....salts of HF differ from the rest of hydracids ...AgF is soluble in water while other AgX dont....due to anamolous behaviour of fluorine
1also fluorine only forms two different salts with metals....eg...NaF and NaHF2
1Although fructose is a ketone, it reacts with Tollens reagent due to some rearragement.
AgCN forms isocyanide n others like KCN, NaCN etc. form cyanides.
Although halides are decactivarors for benzene ring they are ortho para directing.
Pls forgive me if they are too silly :( :( :(
1
13(CH3)3-I ----KCN(in aq ethanol)----> (CH3)2=CH2(major product)
1in IS block elements, all of the halides formed are ionic...except those of lithium halides dey are covalent due to the lesser electronegativity differences
11I know u guys are fed up of this exception .....but still
http://targetiit.com/iit_jee_forum/posts/colours_again_961.html
[3]
1electron affinity of flourine and chlorine...the simplest and most remembered exception...:P
111 exception to be remembered
ORDER OF μ(DIPOLE MOMENTS)
CH3Cl>CH3F>CH3Br>CH3I
1.85 D 1.81D 1.8D 1.64D
11Among its group members Boron has an unusual structure called Icosahedra
211 exception to be remembered
ORDER OF μ(DIPOLE MOMENTS)
CH3Cl>CH3F>CH3Br>CH3I
1.85 D 1.81D 1.8D 1.64D
^^^^ iska reason kya tha main bhool gaya ...... shayad size ka kuch tha ..... [12]
1its not exception, buta generalised rule:
the E A of first member of representative element grup is lower than 2nd member coz of small size and which results in strong electron-electron repulsions
1its also not actually an exception, but a pitfall:
but let me ask it first...how many natural elements r there??????
i'll answer to it tomorrow...
1got dis on googlin....
90
but not sure abt it as d source is not reliable...
1correct, but havent u heard that natural elements=92???
ans is correct, but we were told "in bachpan"that 92 natural...wtz wrong in that?