Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This is due to the
formation of
1. CrO2-4
2. Cr2(SO3)3
3. CrSO4
4. Cr2(SO4)3
identify the incorrect statement among the following:
(1) There is a decrease in the radii of the atoms or ions as one proceeds from La to Lu.
(2) Lanthanoid contraction is the accumulation of successive shrinkages
(3) As a result of lanthanoid contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements
(4) Shielding power of 4f electrons is quite weak
More number of oxidation states are exhibited by the actinoids than by the lanthanoids. The main reason for this is:
(1) More energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
(2) Lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
(3) Greater metallic character of the lanthanoids than that of the corresponding actinoids
(4) More active nature of the actinoids
A metal M and its compound can give the following observable changes in a consequence of reactions
M [Colourless solutions] [White precipitate] [Colourless solutions] [White precipitate]
(1) Mg
(2) Pb
(3) Zn
(4) Sn
Which of the following solid salt on heating with solid and conc. orange red vapours are evolved which turn aqueous NaOH solution yellow?
(a)NaBr (b) NaCl
(c) (d) NaI
Which of the following is true for the species configuration ?
(1) is reducing in nature
(2) is oxidising in nature.
(3) Both (A) and (B)
(4) None of these
Which of the following increasing order of oxidising power is correct for the following species?
(A)
(B)
(C)
(D)
Anhydrous ferric chloride is prepared by
(1) Heating hydrated ferric chloride at a high temperature in a stream of air.
(2) Heating metallic iron in a stream of dry chlorine gas.
(3) Reaction of ferric oxide with HCl (aq).
(4) Reaction of metallic iron with HCl (aq).
Anhydrous ferrous sulphate on heating gives :
1. Both
2.
3.
4.
Select the correct statement :
(1) reduces to metallic Ag.
(2) Organic tissues turn black by reducing it to Ag.
(3) is soluble in .
(4) All are correct statements.
The yellow colour solution of changes to orange-red on passing gas due to the formation of :
(1)
(2)
(3)
(4)
Which of the following products are formed when potassium bromide reacts with potassium permanganate in alkaline pH?
1.
2.
3.
4.
Which one of the following statements is not correct
1. Nickel forms Ni(CO)4
2. All the transition metals form mono-metallic carbonyls
3. Carbonyl are formed by transition metals
4. Transition metals form complexes
The radius of La3+ (atomic number of La=57) is 1.06 . Which one of the following given values will be closest to the radius of Lu3+ (atomic number of Lu =71)
(1) 1.60
(2) 1.40
(3)1.96
(4)0.85
Match the underlined atom in Column A with oxidation number in Column B.
A B
(a) [Fe(CN)5O]2- 0(I)
(b) [Ag(CN)2]- 3(II)
(c) [Cr(en)3]3+ 1(III)
(d) Ni(CO)4 2(IV)
a b c d
(A) I II III IV
(B) II III IV I
(C) IV III II I
(D) II III I IV
By calculating Eo value of the following reaction,which one of the following reaction are spontaneous.
Given
(A) Only d
(B) Only b
(C) Both c & d
(D) Both a & c
When excess of SnCl2 is added to HgCl2, the substance formed is
1. Hg2Cl2
2. Sn
3. Hg
4. Cl2
A mixture of Mn2+ & Zn2+ can be separated by using an excess of
(1) NH4OH
(2) NaOH
(3) H2SO4
(4) HNO3
The incorrect statement regarding the transition metals is:
1. | They are malleable and ductile. |
2. | They have high melting and boiling points. |
3. | They crystallise with body-centered cubic and hexagonal close-packed structure only. |
4. | They show variable oxidation states although not always. |
Cerium(Z=58) is an important member of lanthanoids. Which of the following statements about cerium is incorrect
(1) The common oxidation states of cerium are +3 and +4.
(2) Cerium (IV) acts as an oxidising agent
(3) The +4 oxidation state of cerium is not known in solutions
(4) The +3 oxidation state of cerium is more stable than the +4 oxidation state.