Ncert Exercises & Solutions

Which of the following lanthanoids show a +2 oxidation state besides the characteristic oxidation state +3 of lanthanoids?

(a) Ce

(b) Eu

(d) Ho

Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

NEETprep Answer: (b,c)

(a) Cerium (Z = 57) = Electronic configuration =

[X e] 4 f^{5} 5 d^{0} 6 s^{2}

Oxidation state of Ce = +3, +4

(b) Europium (Z= 63) = Electronic configuration =

[X e] 4 f^{7} 5 d^{0} 6 s^{2}

Eu = +2 , +3

[X e] 4 f^{14} 5 d^{0} 6 s^{2}

Oxidation state of Yb = +2 , +3

(d) Holmium (Z = 67) = Electronic configuration =

[X e] 4 f^{11} 5 d^{0} 6 s^{2}

Oxidation state of Ho = +3