BITSAT 10 CHEM

CrO4- + H⁺ gives Cr₂O₇^2- + H2O

So option ii correct

The number of moles of KMnO4 that will be needed to react completely with one mole of ferrous oxalate in acidic solution is
3/5
2/5
4/5
1

Shreyan that's just one calcium salt.... You must have seen my image...thats how they form.
The (b) option corresponds to the calcium salt you are referring to(for producing acetone).
Actually the end product has to have calcium carbonate. I suppose that's why..

steric hndrance

Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of
insolubility
instability
inductive effect
steric hindrance

@ Pritish: one doubt....are u sure that heating of calcium formate will produce HCHO? the mechanism i read (for calcium acetate) was this:

How can HCHO form using this mech?

ACTALDEHYDE

i<iii<ii<iv

Compare the stability of their conjugate bases.
I - CO₃^2-
II - H₂O
III - SO₄^2-
IV - SO₃F^-

The stablest out of these is II as it has no formal charge. Next in line is IV as it is stabilised by -I effect of fluorine.
Now the battle is between carbonate and sulfate anions. You may recall that sulfuric acid and carbonic acid both have two acid dissociation constants, of which for sulfuric acid the second one is small. It is not so for carbonic acid.
Hence I is more stable than III.
So the order of stability of conjugate bases is
II > IV > I > III
In the same order follows their acid strength (the acid with the most stable conjugate base is most likely to lose a proton) -:
II > IV > I > III

Four species are listed below
(i) HCO3- (ii) H3O+ (iii) HSO4- (iv) HSO3F
Which of the following is the correct sequenece of their acid strength?
iii < i < iv < ii
iv < ii < iii < i
ii < iii < i < iv
i < iii < ii < iv

Ans i < iii < ii < iv