19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The electronic configurations of Eu (Atomic No. 63), Gd (Atomic No. 64) and Tb (Atomic No. 65) are (NEET-I 2016)
Which of the following processes does not involve oxidation of iron? (NEET 2015)
Which of the following statements about the interstitial compounds is incorrect? (NEET 2013)
Sc (Z = 21) is a transition element but Zn (Z = 30) is not because (NEET 2013)
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
reacts with OH– as CrO 2CrO 2H Cr O H O -> Cr O The change in oxidation number of Cr is
CrO3 dissolves in aqueous NaOH to give (a) CrO
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
Which of the following coordination entities should be expected to absorb light of lowest frequency?[AIIMS2009]
Assertion: CO and CN are referred as acid ligands. Reasaon: In CO and CN vacant type orbitals are present. [AIIMS 2009]
Assertion: K4[Fe(CN)6] is diamagnetic and [Fe(H2O)6]Cl3 is paramagnetic. Reason: Hybridisation of central metal in K4[Fe(CN)6] is sp3d2, while in [Fe(H2O)6]Cl3 is d 2sp 3. [AIIMS 2009]
Again for [Fe(H2O)6]Cl3, since H2O is a weak field ligand, the unpaired electrons will not get paired up. Thus the hybridization of Fe will besp 3d 2. So, the reason is not correct. Hence, the correct option is (c).
The coordination compound of which one of the following compositions will produce two equivalents of AgCl on reaction with aqueous silver nitrate solution? [J&K CET 2009]
The existence of two different coloured complexes with the composition [Co(NH3)4Cl2] + is due to [CBSE AIPMT2010]
Crystal field stabilisation energy for high spin d octahedral complex is [CBSE AIPMT2010]
Which of the following complex ion is not expected to absorb visible light? [CBSE AIPMT 2010]
Assertion: If 4 for [Cu(NH3)4] 2+ is 2.1 × 10 13, its instability constant is 4.76 × 10 –14. Reason: Overall dissociation equilibrium constant varies inversely with formation constant. [AIIMS2010]
Which of the following is a coordination compound?