Chemistry Question Bank

The lead of the lead pencils melts at (AIIMS 2009) p-BLOCK (Group 13 - 14)

Which of the following is a false statement ?

A mixture of boron trichloride and hydrogen is subjected to silent electric discharge to form ‘A’ and HCl. ‘A’ is mixed with NH₃ and heated to 200 °C to form ‘B’. The formula of ‘B’ is:

Graphite is a good conductor of electricity. Its electrical conductivity is due to the fact that (CPMT 2010)

Heating an aqueous solution of aluminium chloride to dryness will give

Na₂B₄O₇.10H₂O is correctly represented as:

Assertion: Silicones are hydrophobic in nature. Reason: Si–O–Si linkages are moisture sensitive. (AIIMS 2006)

Boron cannot form which one of the following anions? (a) BF⁻ (b) BH⁻

Which one of the following is the correct statement ?

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)

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…

BCl₃ does not exist as a dimer but BH₃ exists as B₂H₆ because

Boron compounds behave as Lewis acids, because of their (AIPMT 1996)

In B₂H₆:

Borazole, B₃N₃H₆ is related to benzene as:

In graphite, electrons are

Which of the following compounds is known as inor- ganic benzene?

The main factor responsible for weak acidic nature of B—F bonds in BF₃ is:

Which of the following types of forces bind together the carbon atoms in diamond? (AIPMT 1992)

H₃BO₃ is:

Boric acid has a polymeric layer structure in which planar BO₃ units are joined by

Boric acid H₃BO₃ and BF₃ have the same number of elec- trons. The former is a solid and the latter is a gas. The reason is:

On hydroloysis, diborane produces

A type of zeolite used to convert alcohols directly into gasoline is

The structure of diborane (B₂H₆) contains :