19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Sodium thiosulphate, Na2S2O3. 5H2O is used in photography to :
Assertion : The melting point of Mn is more than that of Fe. Reason : Mn has higher number of unpaired e– than Fe in atomic state.
Assertion : Hg is the only metal that is liquid at 0ºC. Reason : It has a very high I.P. and weak metallic bond.
Which of the following compounds is expected to be coloured ?
Na2CrO4 on treatment with lead acetate gives a precipitate. This precipitate is dried and the solid is used as a pigment for road signs and markings. The solid is known as
Acidified K2Cr2O7 on treatment with KI produces
When hydrogen peroxide is added to an acidic solution of a dichromate, the most probable product is
reacts with H+ as The change in oxidation number of Cr is
KMnO4 in an acidic medium oxidizes (a) C O to CO2 (b) N2H4 to N2 (c) HSO to SO
Which of the following is an incorrect statement ? (a)In a redox reaction in acidic medium, KMnO4 produces Mn2+ ions. (b)In a redox reaction in strongly alkaline medium, KMnO4produces MnO ions. (c)In a redox reaction …
KMnO4 in an acidic medium will not oxidize (a) (b)
is prepared by treating a solution containing Mn2+ ions with a very strong oxidizing agent such as
KMnO4 is manufactured on a large scale by (a)fusing MnO2 with KOH and then oxidizing the fused mixture with KNO3
Which of the following compounds is green in colour ?
Which of the following oxides of chromium is amphoteric in nature ?
The transition metals sometimes form nonstoichiometric compounds. These compounds have (a) definite structures and definite proportions
The transition elements are
Which of the following ions is expected to the coloured in solution ?
Heat 4K Cr O 4K CrO 3O X -> . In the above reaction X is
Which of the following electronic configurations represents Fe3+ ?
Which of the following does not possess unpaired electrons ?
Which of the following ions has the maximum number of unpaired d electrons ?
Chromyl chloride, CrO2Cl2, is prepared by heating a mixture of
Which of the following is not true about the transition elements ?
Sodium chromate is prepared by (a)fusing chromite (FeCr2O4) with sodium chloride in air (b)fusing chromite (FeCr2O4) with sodium hydroxide in air (c)fusing (NH4)2Cr2O7 with sodium hydrogen sulphate in nitrogen