The following reaction is at equilibrium ,
`underset("Yellow")(Fe_((aq))^(3+))+ underset("Colourless")(SCN_((aq)))rArrunderset("Deep red") ([Fe(SNC)]_((aq))^(2+))`
`K_(c)=([Fe(SCN)])/([Fe^(3+)][SCN])`
In the above reaction , colour intensity of red colour can be increased by :- (A) addition of KSCN (B) addition of oxalic acid which reacts with F e 3 + ions (C) addition of H g 2 + ions which react with S C N − ions (D)red colour intensity cannot be changed

Options

A. `AgNO_(3)`
B. `HgCl_(2)`
C. `H_(2)C_(2)O_(4)`
D. `H_(2)O`

Answer

A, B, C