JIPMER2018Chemistryp Block Elements (Group 15, 16, 17 & 18)
Which of the following is correct statement?
Options
- AAluminium dissolves in dilute mineral acids but is made passive by concentrated nitric acid.
- BAluminium vessel can be used as storage of NaOH .
- CAluminium chloride does not dissociate in water.
- DAlF ₃ is soluble in anhydrous HF .
Correct answer
A. Aluminium dissolves in dilute mineral acids but is made passive by concentrated nitric acid.
Step-by-step solution
- Aluminium is made passive by HNO ₃ due to formation of oxide layer. Hence, HNO ₃ does not react further but other acids react. gathered 2 Al +6 HCl 2 AlCl ₃+3 H ₂ 2 Al +3 H ₂ SO ₄ Al ₂ ( SO ₄ )₃+3 H ₂ gathered - NaOH reacts with Al as 2 NaOH +2 Al 2 NaAlO ₂+3 H ₂+2 H ₂ O Thus, NaOH cannot be stored in a vessel made of Al. - Aluminium chloride dissociate in water. - AlF ₃ is insoluble in anhydrous HF. Thus, the only correct statement among the given options is (1).