NEET2015Chemistryp Block Elements (Group 13 & 14)Actual
The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence:
Options
- AG a < I n < A l < T l
- BA l < G a < I n < T l
- CT l < I n < G a < Al
- DI n < T l < G a < A l
Correct answer
B. A l < G a < I n < T l
Step-by-step solution
The inert-pair effect is the tendency of the two electrons in the outermost atomic-s orbital to remain unshared in compounds of post-transition elements. Inert-pair effect is seen in the elements of 13th,14th, 15th and 16th groups. Due to the inert-pair effect elements down the group exhibit oxidation state which is 2 units lesser than the elements above them. Stability of +1 oxidation state due to inert pair effect is in the order A l < G a < I n < T l