Gun metal is an alloy of:
1.Cu and Al
2.Cu and Sn
3.Cu, Zn and Sn
4.Cu, Zn and Ni
The pair that has similar atomic radii is
1.Mn and Re
2.Ti and Hf
3.Sc and Ni
4.Mo and W
According to IUPAC nomenclature sodium nitroprusside dihydrate is named as
1.Sodium pentacyanonitrosylferrate (III)
2.Sodium nitroferrocyanide
3.Sodium nitroferricyanide
4.Sodium pentacyanonitrosylferrate (II)
In Fe(CO)5, the Fe-C bond possesses:
1.ionic character
2.sigma character only
3.pi character
4.both sigma and pi characters
Silver nitrate produces a black stain on the skin due to
1.being a strong reducing agent
2.its corrosive action
3.formation of complex compound
4.its reduction to metallic silver
The number of unpaired electrons in gaseous species of Mn3+, Cr3+Â and V3+Â respectively are:
1.4, 4 and 2
2.3, 3 and 2
3.4, 3 and 2
4.3, 3 and 3
When potassium ferrocyanide crystals are heated with concentrated sulphuric acid, the gas evolved is
1.sulphur dioxide
2.ammonia
3.carbon monoxide
4.carbon dioxide
Which of the following products are obtained when Na2CO3Â is added to a solution of copper sulphate?
1.Basic copper carbonate , sodium sulphate and CO2
2.Copper hydroxide, sodium sulphate and CO2
3.Copper carbonate, sodium sulphate and CO2
4.Copper carbonate and sodium sulphate
Which one of the following elements shows the maximum number of different oxidation states in its compounds?
1.Eu
2.La
3.Cd
4.Am
Zinc and mercury do not show variable valency like d-block elements because
1.they are soft
2.their d-shells are complete
3.they have only two electrons in the outermost subshell.
4.their d-shells are incomplete