General
✓✗The common oxidation state of thorium is
- +2
- +6
- +4
- +3
General
✓✗In which of the following compounds does a transition metal show an oxidation state of +7?
- Mn2O7
- V2O5
- Fe2O3
- CrO3
General
✓✗The electronic configurations of four elements are given below. Which element does NOT belong to the same family as the others?
- [Ne]3s23p5
- [Xe]4f145d106s2
- [Ar]3d104s2
- [Kr]4d105s2
General
✓✗Which catalyst is used in the contact process for sulphuric acid?
- Ni
- Fe
- V2O5
- TiCl4
General
✓✗In the preparation of K2Cr2O7, sodium chromate is converted into sodium dichromate by
- adding NaOH
- acidification with sulphuric acid
- heating with carbon
- adding KCl
General
✓✗Which one of the following ions exhibits d−d transition and paramagnetism as well?
- CrO42−
- Cr2O72−
- MnO42−
- MnO4−
General
✓✗In the dichromate ion, the two Cr atoms are linked through
- a Cr−Cr bond
- one bridging oxygen atom, with two CrO4 tetrahedra sharing a corner
- two bridging oxygen atoms
- three bridging oxygen atoms
General
✓✗KMnO4 reacts with oxalic acid according to the equation
2MnO4− + 5C2O42− + 16H+ → 2Mn2+ + 10CO2 + 8H2O
Here, 20 mL of 0.1 M KMnO4 is equivalent to
2MnO4− + 5C2O42− + 16H+ → 2Mn2+ + 10CO2 + 8H2O
Here, 20 mL of 0.1 M KMnO4 is equivalent to
- 50 mL of 0.5 M H2C2O4
- 20 mL of 0.1 M H2C2O4
- 20 mL of 0.5 M H2C2O4
- 50 mL of 0.1 M H2C2O4
General
✓✗Which of the following groups of elements are called coinage metals?
- Sc, Y and La
- Fe, Co and Ni
- Cu, Ag and Au
- Zn, Cd and Hg
General
✓✗Eu2+ is a strong reducing agent because
- it changes to the common +3 oxidation state
- it is diamagnetic
- it has no f electrons
- it has the 4f14 configuration
General
✓✗25 mL of 0.02 M KMnO4 is exactly reduced by an acidified oxalic acid solution of concentration 0.05 M. The volume of oxalic acid solution used is
- 62.5 mL
- 10 mL
- 50 mL
- 25 mL
General
✓✗A magnetic moment of 2.84 BM is given by (At. nos. Ni = 28, Ti = 22, Cr = 24, Co = 27)
- Cr2+
- Ni2+
- Ti3+
- Co2+
General
✓✗Brass is an alloy of
- nickel and chromium
- copper and zinc
- iron and carbon
- copper and tin
General
✓✗The enthalpy of atomisation in the first transition series is maximum at about
- Sc
- Cu
- Zn
- the middle of the series (V/Cr)
General
✓✗Assertion: KMnO4 is not used as a primary standard.
Reason: KMnO4 solution decomposes slowly and the solid is often not completely pure.
Reason: KMnO4 solution decomposes slowly and the solid is often not completely pure.
- Both Assertion and Reason are true and Reason is the correct explanation of Assertion
- Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
- Assertion is true but Reason is false
- Both Assertion and Reason are false