When lanthanoids ( \(\mathrm{\mathrm{Ln})}\) are heated with sulphur, then \({\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}\) are formed. Their sulphides \(\left( {{\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}} \right)\) are highly stable because \(\mathrm{\mathrm{Ln}}\) is in +3 oxidation state.
MHTCET - 2016
CHXII08:THE D- & F-BLOCK ELEMENTS
321692
What happens when Lu reacts with cold water?
1 No reaction
2 Dissolves in water
3 \(\mathrm{\mathrm{Lu}_{2} \mathrm{O}_{3}}\) is formed
4 Forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
Explanation:
Lu reacts with cold water forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
NCERT Exemplar
CHXII08:THE D- & F-BLOCK ELEMENTS
321693
Select the INCORRECT statement about the chemical properties of lanthanoids (Ln).
1 They produce \(\mathrm{H}_{2}\) gas with dil. acid.
2 They produce \(\mathrm{Ln}_{2} \mathrm{O}_{3}\) type oxides when burnt in presence of \(\mathrm{O}_{2}\).
3 At elevated temperatures, Ln reacts with nitrogen to produce \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type salt.
4 React with water at room temperature to produce \(\mathrm{Ln}(\mathrm{OH})_{3}+\mathrm{H}_{2}\).
Explanation:
Lanthanoids common oxidation state is +3 , So they form LnN type nitrides. (not \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type).
CHXII08:THE D- & F-BLOCK ELEMENTS
321694
Strongest and the weakest bases among the hydroxides of lanthanides are respectively
1 \(\mathrm{Lu}(\mathrm{OH})_{3}\) and \(\mathrm{La}(\mathrm{OH})_{3}\)
2 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Lu}(\mathrm{OH})_{3}\)
3 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Ce}(\mathrm{OH})_{3}\)
4 \(\mathrm{Pm}(\mathrm{OH})_{3}\) and \(\mathrm{Nd}(\mathrm{OH})_{3}\)
Explanation:
Due to lanthanide contraction, ionic size decreases from \(\mathrm{La}^{3+}\) to \(\mathrm{Lu}^{3+}\) hence, basic strength decreases from \(\mathrm{La}(\mathrm{OH})_{3}\) to \(\mathrm{Lu}(\mathrm{OH})_{3}\)
CHXII08:THE D- & F-BLOCK ELEMENTS
321695
The separation of lanthanoids by the ion exchange method is based on
1 The solubilty of the nitrates
2 Size of the hydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
3 Size of the unhydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
When lanthanoids ( \(\mathrm{\mathrm{Ln})}\) are heated with sulphur, then \({\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}\) are formed. Their sulphides \(\left( {{\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}} \right)\) are highly stable because \(\mathrm{\mathrm{Ln}}\) is in +3 oxidation state.
MHTCET - 2016
CHXII08:THE D- & F-BLOCK ELEMENTS
321692
What happens when Lu reacts with cold water?
1 No reaction
2 Dissolves in water
3 \(\mathrm{\mathrm{Lu}_{2} \mathrm{O}_{3}}\) is formed
4 Forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
Explanation:
Lu reacts with cold water forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
NCERT Exemplar
CHXII08:THE D- & F-BLOCK ELEMENTS
321693
Select the INCORRECT statement about the chemical properties of lanthanoids (Ln).
1 They produce \(\mathrm{H}_{2}\) gas with dil. acid.
2 They produce \(\mathrm{Ln}_{2} \mathrm{O}_{3}\) type oxides when burnt in presence of \(\mathrm{O}_{2}\).
3 At elevated temperatures, Ln reacts with nitrogen to produce \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type salt.
4 React with water at room temperature to produce \(\mathrm{Ln}(\mathrm{OH})_{3}+\mathrm{H}_{2}\).
Explanation:
Lanthanoids common oxidation state is +3 , So they form LnN type nitrides. (not \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type).
CHXII08:THE D- & F-BLOCK ELEMENTS
321694
Strongest and the weakest bases among the hydroxides of lanthanides are respectively
1 \(\mathrm{Lu}(\mathrm{OH})_{3}\) and \(\mathrm{La}(\mathrm{OH})_{3}\)
2 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Lu}(\mathrm{OH})_{3}\)
3 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Ce}(\mathrm{OH})_{3}\)
4 \(\mathrm{Pm}(\mathrm{OH})_{3}\) and \(\mathrm{Nd}(\mathrm{OH})_{3}\)
Explanation:
Due to lanthanide contraction, ionic size decreases from \(\mathrm{La}^{3+}\) to \(\mathrm{Lu}^{3+}\) hence, basic strength decreases from \(\mathrm{La}(\mathrm{OH})_{3}\) to \(\mathrm{Lu}(\mathrm{OH})_{3}\)
CHXII08:THE D- & F-BLOCK ELEMENTS
321695
The separation of lanthanoids by the ion exchange method is based on
1 The solubilty of the nitrates
2 Size of the hydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
3 Size of the unhydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
When lanthanoids ( \(\mathrm{\mathrm{Ln})}\) are heated with sulphur, then \({\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}\) are formed. Their sulphides \(\left( {{\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}} \right)\) are highly stable because \(\mathrm{\mathrm{Ln}}\) is in +3 oxidation state.
MHTCET - 2016
CHXII08:THE D- & F-BLOCK ELEMENTS
321692
What happens when Lu reacts with cold water?
1 No reaction
2 Dissolves in water
3 \(\mathrm{\mathrm{Lu}_{2} \mathrm{O}_{3}}\) is formed
4 Forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
Explanation:
Lu reacts with cold water forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
NCERT Exemplar
CHXII08:THE D- & F-BLOCK ELEMENTS
321693
Select the INCORRECT statement about the chemical properties of lanthanoids (Ln).
1 They produce \(\mathrm{H}_{2}\) gas with dil. acid.
2 They produce \(\mathrm{Ln}_{2} \mathrm{O}_{3}\) type oxides when burnt in presence of \(\mathrm{O}_{2}\).
3 At elevated temperatures, Ln reacts with nitrogen to produce \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type salt.
4 React with water at room temperature to produce \(\mathrm{Ln}(\mathrm{OH})_{3}+\mathrm{H}_{2}\).
Explanation:
Lanthanoids common oxidation state is +3 , So they form LnN type nitrides. (not \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type).
CHXII08:THE D- & F-BLOCK ELEMENTS
321694
Strongest and the weakest bases among the hydroxides of lanthanides are respectively
1 \(\mathrm{Lu}(\mathrm{OH})_{3}\) and \(\mathrm{La}(\mathrm{OH})_{3}\)
2 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Lu}(\mathrm{OH})_{3}\)
3 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Ce}(\mathrm{OH})_{3}\)
4 \(\mathrm{Pm}(\mathrm{OH})_{3}\) and \(\mathrm{Nd}(\mathrm{OH})_{3}\)
Explanation:
Due to lanthanide contraction, ionic size decreases from \(\mathrm{La}^{3+}\) to \(\mathrm{Lu}^{3+}\) hence, basic strength decreases from \(\mathrm{La}(\mathrm{OH})_{3}\) to \(\mathrm{Lu}(\mathrm{OH})_{3}\)
CHXII08:THE D- & F-BLOCK ELEMENTS
321695
The separation of lanthanoids by the ion exchange method is based on
1 The solubilty of the nitrates
2 Size of the hydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
3 Size of the unhydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
When lanthanoids ( \(\mathrm{\mathrm{Ln})}\) are heated with sulphur, then \({\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}\) are formed. Their sulphides \(\left( {{\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}} \right)\) are highly stable because \(\mathrm{\mathrm{Ln}}\) is in +3 oxidation state.
MHTCET - 2016
CHXII08:THE D- & F-BLOCK ELEMENTS
321692
What happens when Lu reacts with cold water?
1 No reaction
2 Dissolves in water
3 \(\mathrm{\mathrm{Lu}_{2} \mathrm{O}_{3}}\) is formed
4 Forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
Explanation:
Lu reacts with cold water forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
NCERT Exemplar
CHXII08:THE D- & F-BLOCK ELEMENTS
321693
Select the INCORRECT statement about the chemical properties of lanthanoids (Ln).
1 They produce \(\mathrm{H}_{2}\) gas with dil. acid.
2 They produce \(\mathrm{Ln}_{2} \mathrm{O}_{3}\) type oxides when burnt in presence of \(\mathrm{O}_{2}\).
3 At elevated temperatures, Ln reacts with nitrogen to produce \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type salt.
4 React with water at room temperature to produce \(\mathrm{Ln}(\mathrm{OH})_{3}+\mathrm{H}_{2}\).
Explanation:
Lanthanoids common oxidation state is +3 , So they form LnN type nitrides. (not \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type).
CHXII08:THE D- & F-BLOCK ELEMENTS
321694
Strongest and the weakest bases among the hydroxides of lanthanides are respectively
1 \(\mathrm{Lu}(\mathrm{OH})_{3}\) and \(\mathrm{La}(\mathrm{OH})_{3}\)
2 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Lu}(\mathrm{OH})_{3}\)
3 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Ce}(\mathrm{OH})_{3}\)
4 \(\mathrm{Pm}(\mathrm{OH})_{3}\) and \(\mathrm{Nd}(\mathrm{OH})_{3}\)
Explanation:
Due to lanthanide contraction, ionic size decreases from \(\mathrm{La}^{3+}\) to \(\mathrm{Lu}^{3+}\) hence, basic strength decreases from \(\mathrm{La}(\mathrm{OH})_{3}\) to \(\mathrm{Lu}(\mathrm{OH})_{3}\)
CHXII08:THE D- & F-BLOCK ELEMENTS
321695
The separation of lanthanoids by the ion exchange method is based on
1 The solubilty of the nitrates
2 Size of the hydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
3 Size of the unhydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
When lanthanoids ( \(\mathrm{\mathrm{Ln})}\) are heated with sulphur, then \({\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}\) are formed. Their sulphides \(\left( {{\rm{L}}{{\rm{n}}_{\rm{2}}}{{\rm{S}}_{\rm{3}}}} \right)\) are highly stable because \(\mathrm{\mathrm{Ln}}\) is in +3 oxidation state.
MHTCET - 2016
CHXII08:THE D- & F-BLOCK ELEMENTS
321692
What happens when Lu reacts with cold water?
1 No reaction
2 Dissolves in water
3 \(\mathrm{\mathrm{Lu}_{2} \mathrm{O}_{3}}\) is formed
4 Forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
Explanation:
Lu reacts with cold water forms \(\mathrm{\mathrm{Lu}(\mathrm{OH})_{3}}\) and \(\mathrm{\mathrm{H}_{2}}\)
NCERT Exemplar
CHXII08:THE D- & F-BLOCK ELEMENTS
321693
Select the INCORRECT statement about the chemical properties of lanthanoids (Ln).
1 They produce \(\mathrm{H}_{2}\) gas with dil. acid.
2 They produce \(\mathrm{Ln}_{2} \mathrm{O}_{3}\) type oxides when burnt in presence of \(\mathrm{O}_{2}\).
3 At elevated temperatures, Ln reacts with nitrogen to produce \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type salt.
4 React with water at room temperature to produce \(\mathrm{Ln}(\mathrm{OH})_{3}+\mathrm{H}_{2}\).
Explanation:
Lanthanoids common oxidation state is +3 , So they form LnN type nitrides. (not \(\mathrm{Ln}_{3} \mathrm{~N}_{2}\) type).
CHXII08:THE D- & F-BLOCK ELEMENTS
321694
Strongest and the weakest bases among the hydroxides of lanthanides are respectively
1 \(\mathrm{Lu}(\mathrm{OH})_{3}\) and \(\mathrm{La}(\mathrm{OH})_{3}\)
2 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Lu}(\mathrm{OH})_{3}\)
3 \(\mathrm{La}(\mathrm{OH})_{3}\) and \(\mathrm{Ce}(\mathrm{OH})_{3}\)
4 \(\mathrm{Pm}(\mathrm{OH})_{3}\) and \(\mathrm{Nd}(\mathrm{OH})_{3}\)
Explanation:
Due to lanthanide contraction, ionic size decreases from \(\mathrm{La}^{3+}\) to \(\mathrm{Lu}^{3+}\) hence, basic strength decreases from \(\mathrm{La}(\mathrm{OH})_{3}\) to \(\mathrm{Lu}(\mathrm{OH})_{3}\)
CHXII08:THE D- & F-BLOCK ELEMENTS
321695
The separation of lanthanoids by the ion exchange method is based on
1 The solubilty of the nitrates
2 Size of the hydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
3 Size of the unhydrated \(\mathrm{\mathrm{M}^{3+}}\) ions
