Multiple Choice QuestionsWhat is the general molecular formula of the product obtained on heating lanthaniods (Ln) with sulphur?
LnS
LnS3
Ln3S2
Ln2S3
Choose the correct matching of transition metal ion and magnetic moment from the codes given below. (Atomic number: Ti = 22, V =23, Fe= 26)
| Transition element | Magnetic moment (BM) |
| A. Titanium (III) | i. 4.9 |
| B. Vanadium (II) | ii. 1.73 |
| C. Iron (II) | iii. 3.87 |
A - ii; B - iii; C - i
A - ii; B - i; C - iii
A - i; B - ii; C - iii
A - i; B - iii; C - ii
How is sodium chromate converted into sodium dichromate in the manufacture of potassium dichromate from chromite ore?
By the action of concentrated sulphuric acid
By roasting with soda ash
By the action of sodium hydroxide
By the action of limestone
A.
By the action of concentrated sulphuric acid
By the action of concentrated sulphuric acid, sodium chromate gets converted into sodium dichromate in the manufacture of potassium dichromate.
Various steps involved are:
Step I: Concentration of the chromite ore by Wilfley method.
Step II: Conversion of the concentrated chromite ore into Na2CrO4. Concentrated
chromite ore is fused with molten Na2CrO3 in the presence of air when Na2CrO4 and Fe2O3 are formed.
Step III: Conversion of Na2CrO4 into Na2Cr2O7. Aqueous solution of Na2CrO4 is acidified to obtain Na2Cr2O7 .
Identify the metal that forms colourless compounds.
Iron (Z = 26)
Chromium (Z = 24)
Vanadium (Z=23)
Scandium (Z =21)
Consider the following statements.
I. La(OH)3 is the least basic among hydroxides of lanthanides.
II. Zr4+ and Hf4+ possess almost the same ionic radii.
III. Ce4+ can act as an oxidising agent.
Which of the above is/are true?
I and III
II and III
II only
I and II
Pick out the correct statement(s).
1. Manganese exhibits +7 oxidation state
2. Zinc forms coloured ions
3. [CoF6]3- is diamagnetic
4. Sc forms +4 oxidation state
5. Zn exhibits only +2 oxidation state
1 and 2
1 and 5
2 and 4
3 and 4
Pick out the correct statements from the following
1.Cobalt (III) is more stable in octahedral complexes.
2. Zinc forms coloured ions or complexes.
3. Most of the d-block elements and their compounds are ferromagnetic.
4. Osmium shows (VIII) oxidation state.
5. Cobalt (II) is more stable in octahedral complex.
1 and 2
1 and 3
2 and 4
1 and 4
Which of the following statements is not correct?
The complexes [NiCl4]2- and [Ni(CN)4]2- differ in the state of hybridization of nickel
The complexes [NiCl4]2- and [Ni(CN)4]2- differ in the magnetic properties
The complexes [NiCl4]2- and [Ni(CN)4]2- differ in geometry
The complexes [NiCl4]2- and [Ni(CN)4]2- differ in primary valencies of nickel
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