19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Standard solution of KNO3 is used to make salt bridge because
Which of the following has been universally accepted as a reference electrode at all temperatures and has been assigned a value of zero volts?
The electrochemical cell stops working after some time because
Which one of the following statements is incorrect regarding an electrochemical cell?
When metallic copper is shaken with a solution of a copper salt, the reaction proceeds. When equilibrium is established at 298 K, [Cu2+]/[Cu+]2 = 1.667 × 106 M–1. If the standard potential of the Cu2+ | Cu half-cell i…
When hydrogen peroxide is added to an acidic solution of a dichromate, the most probable product is
Acidified K2Cr2O7 on treatment with KI produces
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
CrO3 dissolves in aqueous NaOH to give (a) CrO
reacts with OH– as CrO 2CrO 2H Cr O H O -> Cr O The change in oxidation number of Cr is
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
Chromyl chloride, CrO2Cl2, is prepared by heating a mixture of
Heat 4K Cr O 4K CrO 3O X -> . In the above reaction X is
Identify the species having an atom in +6 oxidation state. (a) (b) [Cr(CN) ] (c)
Which of the following compounds is expected to be coloured ?
Which of the following compounds is colourless?
The compound ZnSO4 is white because (a)charge is transferred from the metal to the oxygen atoms (b)electron transfer to d level does not occur as the level is already filled to capacity in zinc
Which one of the following oxides of chromium is amphoteric in nature ?
The value of magnetic moment ( spin only) for Cu2+ in CuSO4.5H2O is
Which of the following statements is incorrect for CrO3 ? (a)It is a bright orange solid.
Deep red-yellow vapour of CrO2Cl2 is passed into an aqueous solution of NaOH. The solution turns
Which of the following oxides of manganese is amphoteric ?
Which of the following oxides of manganese is stable as well as strongly acidic ?
HgCl reacts with mercury in an iron vessel to form mercurous chloride. HgCl + Hg Hg Cl Δ -> 2. Mercurous chloride can also be prepared by the reduction of mercury chloride by tin. 2+ 2HgCl + SnCl Hg Cl SnCl ->
Chemically philosopher of wool is :