Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
Answer
(1) Both Statement I and Statement II are true
Solution
Statement I: E Al3+/Al = −1.66 V and E Tl3+/Tl = +1.26 V
⇒ Al readily loses electrons to form Al3+ (highly electropositive), while Tl3+ is unstable and is a strong oxidising agent
∴ Al is more electropositive than Tl ⇒ Statement I is true.
Statement II: As per NCERT, the sum of the first three ionisation enthalpies of boron is very high, which prevents it from forming B3+ ions; so boron forms only covalent compounds.
Al has a much lower sum of ionisation enthalpies ⇒ forms Al3+ ions ⇒ Statement II is true.
Answer: (1)