19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The main factor responsible for weak acidic nature of B—F bonds in BF3 is:
Which of the following compounds are formed when boron trichloride is treated with water?
Boron is unable to form BF - ions due to
The element which exists in liquid state for a wide range of temperature and can be used for measuring high temperature is
Which of the following oxides is acidic in nature ?
Which of the following hydroxides is acidic ?
Trimethylammonia is pyramidal whereas trisilylammonia is a planar molecule. Why ?
Maximum ability of catenation is shown by
Compound (B) is:
Compound (A) is:
Aluminium becomes passive in:
Which one of the following metals cannot be extracted by using Al as a reducing agent?
Assertion : In water, orthoboric acid behaves as a weak monobasic acid. Reason : In water, orthoboric acid acts as a proton donor.
Assertion : Boron is p block element. Reason : Last electron entres in p sub shell.
Assertion : Boron always forms covalent bond. Reason : The small size of B3+ favours formation of co- valent bond.
Assertion : AlF3 is soluble in KF but addition of BF3 brings its precipitation. Reason BF3 is more acidic than AlF3.
Assertion : BF3 is a weaker Lewis acid than BCl3. Reason : BF3 molecule is stabilized to a greater extent than BCl3 by B—F p-bonding.
Assertion : Al(OH)3 is amphoteric in nature. Reason : Al—O and O—H bonds can be broken with equal ease in Al (OH)3.
Match the column I with column II and mark the appropriate choice. Column I Column II (A) Galena (i) Abrasive (B) Diamond (ii) Metal carbonyls (C) Carbon monoxide (iii) Hydrides of Si (D) Silanes (iv) An ore of lead
Which of the following compounds is used in cosmetic surgery? (Odisha NEET 2019)
Which of the following species is not stable? (NEET 2019)
Which of the following is incorrect statement? (NEET 2019)
The correct order of atomic radii in group 13 elements is (NEET 2018)
MF which one of the following elements is unable to form ion? (NEET 2018)
It is because of inability of ns2 electrons of the valence shell to participate in bonding that (NEET 2017)