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Tuesday 30 August 2016

General Science(Chemistry)
1.      Which of  the following is used for separation and of purification of organic compounds ?
1.Chromatography
2.Crystallisation
3.Osmosis
4.Reverse Osmosis
5.None of these
Answer & Explanation
Answer – 1.Chromatography
Explanation :
To separate Organic compounds with the help of Column Chromatographic technique.It is useful methods for the separation and purification of both solids and liquids
2.      Blue colour is related to
1.Copper Oxide
2.Cobalt Oxide
3.Iron Oxide
4.Lead Oxide
5.None of these
Answer & Explanation
Answer – 2.Cobalt Oxide
Explanation :
Cobalt(II) oxide or cobalt monoxide is an inorganic compound that appears as olive-green to red crystals, or as a greyish or black powder
3.      Crook’s glass contains which of the following ?
1.Cesium Oxide
2.Lead Oxide
3.Tin Oxide
4.Potassium
5.None of these
Answer & Explanation
Answer – 1.Cesium Oxide
Explanation :
Crook’s glass contains cesium oxides.
4.      MnO2   is used as a substance to make which colour ?
1.Pink
2.Blue
3.Violet
4.Orange
5.None of these
Answer & Explanation
Answer – 3.Violet
Explanation :
MnOis an secondary alloy addition to steel and can make violet colored glass.
5.      Green colour is given by
1.Sodium Oxide
2.Manganese Oxide
3.Copper Oxide
4.Chromium oxide
5.None of these
Answer & Explanation
Answer – 4.Chromium oxide
Explanation :
Chromium oxides are also used as a green color in glass making and as a glaze in ceramics
6.      ……………… is known as fool’s gold
1.Iron Acetate
2.Iron Oxide
3.Iron Pyrite
4.Iron Nitrate
5.None of these
Answer & Explanation
Answer – 3.Iron Pyrite
Explanation :
The mineral pyrite, or iron pyrite, also known as fool’s gold, is an iron sulfide with the chemical formula FeS2.
7.      Which is used to kill rats ?
1.Potassium Sulphate
2.Zinc Nitrate
3.Zinc Phosphate
4.Zinc Phosphide
5.None of these
Answer & Explanation
Answer – 4.Zinc Phosphide
Explanation :
The dangers of zinc phosphide, a poison used to kill gophers and moles, has hit the press.
8.      Silver Spoon is not used with boiling egg because it makes which of the following changes ?
1.Poisonous
2.Colour changes
3.Gas production
4.Odour smell
5.None of these
Answer & Explanation
Answer – 2.Colour changes
Explanation :
A silver plate turn black when a boiled egg is placed on it.
9.      ……………….is also known as Flower of Zinc
1.ZnS
2.ZnO
3.ZnCl
4.ZnO2
5.None of these
Answer & Explanation
Answer – 2.ZnO
Explanation :
ZnO Also called flowers of zinc, philosopher’s wool.
10.  Which of the following gas is used in Holme’s signals ?
1.Bromine
2.Arsine
3.Phosphine
4.Fluorine
5.None of these
Answer & Explanation

Answer – 3.Phosphine
Explanation :
The spontaneous combustion of phosphine is technically used in Holme’s signals.