d- and f-Block Elements · Question 45

Which one of the following does not correctly represent the correct order of the property indicated against it?

1. Ti < V < Cr < Mn : increasing number of oxidation states
2. Ti3+ < V3+ < Cr3+ < Mn3+ : increasing magnetic moment
3. Ti < V < Cr < Mn : increasing melting points
4. Ti < V < Mn < Cr : increasing 2nd ionization enthalpy

Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential ( E M2+/M ) value has a positive sign?

1. Co (Z = 27)
2. Ni (Z = 28)
3. Cu (Z = 29)
4. Fe (Z = 26)

Identify the alloy containing a non-metal as a constituent in it.

1. Invar
2. Steel
3. Bell metal
4. Bronze

Which of the statements is not true?

1. On passing H2S through acidified K2Cr2O7 solution, a milky colour is observed.
2. Na2Cr2O7 is preferred over K2Cr2O7 in volumetric analysis.
3. K2Cr2O7 solution in acidic medium is orange.
4. K2Cr2O7 solution becomes yellow on increasing the pH beyond 7.

For the four successive transition elements (Cr, Mn, Fe and Co), the stability of +2 oxidation state will be there in which of the following order? (At. nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)

1. Mn > Fe > Cr > Co
2. Fe > Mn > Co > Cr
3. Co > Mn > Fe > Cr
4. Cr > Mn > Co > Fe

Acidified K2Cr2O7 solution turns green when Na2SO3 is added to it. This is due to the formation of

1. Cr2(SO4)3
2. CrO42-
3. Cr2(SO3)3
4. CrSO4

Which of the following oxidation states is the most common among the lanthanoids?

1. 4
2. 2
3. 5
4. 3

Which of the following ions will exhibit colour in aqueous solutions?

1. La3+ (Z = 57)
2. Ti3+ (Z = 22)
3. Lu3+ (Z = 71)
4. Sc3+ (Z = 21)

Which of the following ions has electronic configuration [Ar]3d6? (At. nos. Mn = 25, Fe = 26, Co = 27, Ni = 28)

1. Ni3+
2. Mn3+
3. Fe3+
4. Co3+

Which of the following pairs has the same size?

1. Fe2+, Ni2+
2. Zr4+, Ti4+
3. Zr4+, Hf4+
4. Zn2+, Hf4+