19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The lead of the lead pencils melts at (AIIMS 2009) p-BLOCK (Group 13 - 14)
Na₂B₄O₇.10H₂O is correctly represented as:
Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not fomed in these conditions?
Graphite is a good conductor of electricity. Its electrical conductivity is due to the fact that (CPMT 2010)
Which of the following will be formed, if we heat an aqueous solution of AlCl₃ to dryness ?
Boric acid is used in carrom boards for smooth gliding of pawns because:
Assertion: Silicones are hydrophobic in nature. Reason: Si–O–Si linkages are moisture sensitive. (AIIMS 2006)
Which one of the following is the correct statement ?
BCl₃ does not exist as a dimer but BH₃ exists as B₂H₆ because
Carbon and silicon belong to (IV) group. The maximum coordination number of carbon in commonly occurring compounds is 4, whereas that of silicon is 6. This is due to (AIPMT 1994)
Boron cannot form which one of the following anions? (a) BF⁻ (b) BH⁻
The main factor responsible for weak acidic nature of B—F bonds in BF₃ is:
Boron compounds behave as Lewis acids, because of their (AIPMT 1996)
Borazole, B₃N₃H₆ is related to benzene as:
Which of the following compounds is known as inor- ganic benzene?
In graphite, electrons are
NaBH₄ + I₂ ® X + Y + Z BF₃ + NaH 450 K ¾¾¾® X + P BF₃ + LiAlH₄ ® X + Q + R X, Y, Z, P, Q and R in the reactions are X Y Z P Q R (a) Na₄B₄O₇ NaI HI HF LiF AlF₃ (b) B₂H₆ NaI H₂ NaF LiF AlF₃ (c) B₂H₆ BH₃ NaI B₃N₃H₆ Al₂F₆…
The power of halides of boron to act as Lewis acids decreases in the order:
Which of the following types of forces bind together the carbon atoms in diamond? (AIPMT 1992)
Boric acid has a polymeric layer structure in which planar BO₃ units are joined by
On hydroloysis, diborane produces
H₃BO₃ is:
The structure of diborane (B₂H₆) contains :
A type of zeolite used to convert alcohols directly into gasoline is
In B₂H₆: