# Homework Solution: (a) What do you understand by the chelate effect? (b) For the following reaction [Ni(NH_3)_6]…

(a) What do you understand by the chelate effect? (b) For the following reaction [Ni(NH_3)_6]^2+ + 3 en [Ni(en)_3]^2+ + 6 NH_3 it is found that Delta_r H degree = 12.1 kJ mol^-1 and Delta_r S degree = 185 J K^-1 mol^-1 in aqueous solution at 298 K. Compute the value of Delta_r G degree and hence the value of the equilibrium constant. Does the entropy term make a significant contribution to the value of Delta_r G degree? (c) Discuss the trend in the values of the equilibrium constant for the following reactions (all in aqueous solution) [Co(H_2O)_6]^2+ + 6 NH_3 [Co(NH_3)_6]^2++ 6 H_2O logK = 5.2 [Co(H_2O)_6]^2+ + 3 en [Co(en)_3]^2+ + 6 H_2O logK = 13.9 [Co(H_2O)_6]^2+ (6-en) [Co(6-en)]^2+ + 6 H_2O logK= 15.8 (6-en is a linear hexadentate ligand, NH_2(CH_2CH_2NH)_4CH_2CH_2NH_2.)

a) chelating effect :

(a) What do you discern by the chelate movables? (b) Ce the subjoined reaction [Ni(NH_3)_6]^2+ + 3 en [Ni(en)_3]^2+ + 6 NH_3 it is institute that Delta_r H mark = 12.1 kJ mol^-1 and Delta_r S mark = 185 J K^-1 mol^-1 in aqueous disruption at 298 K. Compute the appraise of Delta_r G mark and future the appraise of the bring-aboutweight immutable. Does the entropy order reach a expressive aid to the appraise of Delta_r G mark? (c) Discuss the incline in the appraises of the bring-aboutweight immutable ce the subjoined reactions (entire in aqueous disruption) [Co(H_2O)_6]^2+ + 6 NH_3 [Co(NH_3)_6]^2++ 6 H_2O logK = 5.2 [Co(H_2O)_6]^2+ + 3 en [Co(en)_3]^2+ + 6 H_2O logK = 13.9 [Co(H_2O)_6]^2+ (6-en) [Co(6-en)]^2+ + 6 H_2O logK= 15.8 (6-en is a rectirectidirect hexadentate ligand, NH_2(CH_2CH_2NH)_4CH_2CH_2NH_2.)

## Expert Rejoinder

a)

chelating movables :

if the ligand has further than individual donar post that is designated chelating ligand. if the metal ion/atom conjoined with chelating ligand that many-sided is further steadfast when the corresponding metal ion conjoined with monodentade ligand . it is due to acception in entropy

b)

$\Delta$Go = $\Delta$Ho – T $\Delta$So

= -12.1 – 298 x (0.185)

= -67.2 kJ / mol

$\Delta$Go = -67.2 kJ / mol

$\Delta$Go = – RT ln K

-67.2 = -8.314 x 10^-3 x 298 x ln K

ln K = 27.13

K = 6.06 x 10^11

makeweight immutable = 6.06 x 10^11

yes it is entropically further ancillary consequently in loving work moles = 6+1 = 7. reactant moles = 1+3 = 4. work moles further than reactant moles so entropically further favorble reaction.

c)