Which two of the following compounds, if any, are epimers ?

Options

A. 1&4
B. 1&3
C. 2&3
D. 3&4

Answer

3

Explanation

`S_(1):(2CaSO_(4).2H_(2)O)overset(393K)rarr2(CaSO_(4)).H_(2)O+3H_(2)O,` above `393K` dead burnt plaster is obtained.
`S_(2):Ca^(2+)+Na_(2)CO_(3)rarrCaCO_(3)darr+2Na^(+)`
`S_(3):Li^(+) lt Na^(+) lt K^(+) lt Kb^(+) lt Cs^(+)`
Bigger hydrated ion moves slower in aqueous solution.