19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The stability of +1 oxidation state increases in the sequence (AIPMT 2009)
The number of isomers possible for disubstituted borazine, B3N3H4X2 is: (AIPMT 2006)
The colour imparted by Co(II) compounds to glass is (AIIMS 2006)
Assertion: Silicones are hydrophobic in nature. Reason: Si–O–Si linkages are moisture sensitive. (AIIMS 2006)
Percentage of lead in lead pencil is (AIPMT 1999)
Which of the following does not show electrical conduction? (AIPMT 1999)
In graphite, electrons are
Boron compounds behave as Lewis acids, because of their (AIPMT 1996)
Aluminium (III) chloride forms a dimer because Aluminium (AIPMT 1995)
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)
The type of hybridisation of boron in diborane is (AIPMT 1999)
The tendency of group 14 elements to show +2 oxidation state increases in the order of
Which of the following ions is the most stable ?
A type of zeolite used to convert alcohols directly into gasoline is
Which of the following is the correct statement about silicones ?
Which one of the following anions is present in the chain structure silicates ? (a) Si O - (b) n (Si O ) - (c) n (SiO ) - (d) SiO - Ans. (c) Sol. There are two general formula of anions of chain silicates are n SiO - …
In SiO , - the tetrahedral molecule, two oxygen atoms are shared in
Glass and cement are two important examples of
Silicon is an important constituent of
Which of the following acids cannot be stored in glass ?
CO2 is not a poisonous gas but there is increase in concentration of CO2 in the atmosphere due to burning of fossil fuels and decompostion of limestone. The increase in concentration of CO2 may lead to
Aluminium chloride exists as dimer, Al2Cl6 in solid state as well as in solution of non-polar solvents such as benzene. When dissolved in water, it gives
Which of the following is not from 14 th group
Match the column I with column II and mark the appropriate choice. Column I Column II (A) Coal gas (i) CO + H2 (B) Synthesis gas (ii) CH4 (C) Producer gas (iii) H2 + CH4 + CO (D) Natural gas (iv) CO + N2
Identify X in the reaction : (steam) X 2H O XO 2H D + ¾¾® +