19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Which glass will not crack when temperature changes ? (DUMET 2006)
When alumina is heated with carbon in nitrogen atmo- sphere, the products are:
Alumina is:
The stability of +1 oxidation state increases in the sequence (AIPMT 2009)
Alumina is:
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
Assertion: Silicones are hydrophobic in nature. Reason: Si–O–Si linkages are moisture sensitive. (AIIMS 2006)
In the purification of bauxite by Hall’s process:
Select the true statements: (i) The formula of the corundum is Al₂O₃. (ii) The formula of cryolite is Na₃AlF₆. (iii) The formula of borax is Na₂B₄O₇.10H₂O (iv) The formula of bauxite is Al₂O₃.H₂O
AIF₃ is soluble in HF only in presence of KF. It is due to the formation of
Heating an aqueous solution of aluminium chloride to dryness will give
An element of group 14 forms two oxides one of which is highly poisonous and neutral. Other oxide can be easily liquefied and compressed to give a solid which is used as a refrigerant under the name of drikold. The el…
The tendency of group 14 elements to show +2 oxidation state increases in the order of
Borax is used as a cleansing agent because on dissolving in water, it gives (RPMT 2010)
Which of the following species is not stable? (NEET 2019)
Which of the following will be formed, if we heat an aqueous solution of AlCl₃ to dryness ?
The lead of the lead pencils melts at (AIIMS 2009) p-BLOCK (Group 13 - 14)
Which of the following is not matched correctly with its use ?
From B₂H₆, all the following can be prepared except:
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:
Which of the following types of forces bind together the carbon atoms in diamond? (AIPMT 1992)
Na B O X H BO . + ® What is X in the reaction ?
Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not fomed in these conditions?
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)
Na₂B₄O₇.10H₂O is correctly represented as: