Potassium manganate (K2MnO4) is formed when
The aqueous solutions of the following salts will be coloured in the case of
Aqueous solution of Co(NO3)2 and CrCl3 in which Co2+ (d7) and Cr3+ (d3) contains incompletely filled d-orbitals are coloured.
Among the following ions which one has the highest paramagnetism?
Highest parmagnetic character will be shown by the ion having maximum number of unpaired electrons in their d-subshells.
25Cr3+ has 3 unpaired electrons ; 26Fe2+ has 4 unpaired electrons
29Cu2+ has 1 unpaired electrons ; 30Zn2+ has no unpaired electrons
So (a), (b) & (c) show paramagnetism. Out of which (b) has the highest paramagnetism.
Which of the following alloys contains(s) Cu and Zn?
Brass : Cu (60-80%), Zn (40-20%); Gun Metal : Cu (87%), Sn (10%), Zn (3%).
In nitroprusside ion the iron and NO exist as FeII and NO+ rather than FeIII and NO. These forms can be differentiated by
The magnetic moment (μ) of a species is related to its number of unpaired electrons (n) in form of following expressions.
The number of unpaired electrons in the given pairs are as follows:
The given combinations differ in the number of unpaired electrons. Hence these can be differentiated by the measurement on the solid state magnetic moment of nitroprusside ion.
Addition of high proportions of manganese makes steel useful in making rails of railroads, because manganese
Mn makes steel harder and increases its elasticity and tensile strength. Further Mn acts as deoxidiser.
MnO reacts with S present in cast iron, gets oxidised and then combine to form slag.
If the bond length of CO bond in carbon monoxide is 1.128Å, then what is the value of CO bond length in Fe(CO)5?
The metal to ligand bonding creates a synergic effect which strengthens the bond between CO and the metal (Fe) leading to contraction of bond between C and O of CO.
The compound(s) that exhibit(s) geometrical isomerism is (are)
Reduction of the metal centre in aqueous permanganate ion involves
In acidic medium
Change in oxidation state of Mn = 7 – 2 = 5
Thus electrons lost = 5
In neutral medium
Change in oxidation state of Mn = 7 – 4 = 3
∴ Electrons lost = 3
Cu2+ ions will react with CN– and SCN– forming [Cu(CN)4]3– and [Cu(SCN)4]3– leading the reaction in the backward direction.
Cu2+ also combines with CuCl2 which reacts with Cu to produce CuCl pushing the reaction in the backward direction.
For the given aqueous reactions, which of the statement (s) is (are) true?
The pair(s) of coordination complexes/ions exhibiting the same kind of isomerism is(are)
Th e pair of complex ion s [Co(NH3)4Cl2]+ and [Pt(NH3)2(H2O)Cl]+ show geometrical isomerism.
The pair of complexes [Pt(NH3)3(NO3)]Cl and [Pt(NH3)3Cl]Br show ionisation isomerism. The other pairs given do not have same type of isomerism.
The pair (s) of reagents that yield paramagnetic species is/are
Na + NH3 (excess) → Dilute solution of Na in liq.
NH3 → Paramagnetic
K + O2 (excess) → KO2 (O2– is paramagnetic)
Cu + HNO3 (dil.) → Cu(NO3)2 + NO (NO is paramagnetic) 2-Ethylanthraquinol + O2 →
2-Ethylanthraquinone + H2O2
(H2O2 is diamagnetic)
The correct statement(s) about Cr2+ and Mn3+ is(are) [Atomic numbers of Cr = 24 and Mn = 25]
Cr2+ is a reducing agent and Mn3+ is an oxidizing agent and both have electronic configuration d4.
Above E° values explains reducing nature of Cr2+ and oxidizing behaviour of Mn3+.
Fe3+ is reduced to Fe2+ by using