Alkali metals can be extracted from their salts by
1.reduction with carbon
2.solution of their halides
3.electrolysis of fused halides
4.reduction with aluminium.
Alkali metals do not exist in free state in mature because these aremetallic in naturehighly electronegative elements.
1.very reactive
2.very volatile
3.metallic in naturehighly electronegative
4.None of these
At high temperature nitrogen combines with calcium carbide to give
1.Calcium cyanide
2.Calcium cynamide
3.Calcium nitride
4.Calcium carbonate.
Beryllium shows diagonal relationship with.
1.Mg
2.Na
3.Al
4.B
Caustic soda is
1.Efflorescent
2.Deliquescent
3.Water repelling
4.Reducing agent.
Chlorophyll the main pigment responsible for absorption of light in plants contains.
1.Calcium
2.Magnesium
3.Sodium
4.Potassium
Froth floatation process is used for the concentration of.
1.Oxide ores
2.Sulphide ores
3.Chloride ores
4.Amalgams
Heating pyrites in air to remove sulphur is known as
1.Calcination
2.Roasting
3.Smelting
4.Bessemerisation.
In which of the following minerals aluminium is not present?
1.Cryolite
2.Mica
3.Feldspar
4.Fluorspar.
Molten sodium chloride conducts electricity due to the presence of
1.Free electrons
2.Free ions
3.Free molecules
4.Atoms of sodium and chlorine.
Potassium is stored under.
1.Water
2.Alcohol
3.Ammonia
4.Kerosene
Slag is formed by reaction between
1.impurities and coke
2.impurities and ore
3.impurities and flux
4.None of these
Smelting is generally carried out in
1.Reverberatory furnace
2.Muffle furnace
3.Bessemer converter
4.Blast furnace.
Sodium hydroxide solution reacts with phosphorus to give phosphine. To bring about this reaction we need
1.White phosphorus and dil. NaOH
2.White phosphorus and conc. NaOH
3.Red phosphorus and dil. NaOH
4.Red phosphorus and conc. NaOH.
Solvays process is used for the manufacture of.
1.sodium metal
2.washing soda
3.potassium chlorate
4.ammonia
The approximate percentage of gypsum in Portland cement is
1.10-15%
2.20-30%
3.30-40%
4.2-3%.
The ignition mixture in Alumino-thermite process contains a mixture of
1.Magnesium powder and barium peroxide
2.Magnesium powder aluminium and barium peroxide
3.Magnesium and aluminium powders
4.Magnesium and aluminium oxide.
The impurities associated with the ore after mining are collectively called.
1.flux
2.slag
3.minerals
4.gangue
The metallic luster exhibited by sodium is explained by
1.Diffusion of sodium ions
2.Oscillation of loose electrons
3.Excitation of free electrons
4.Excitation of free electrons
The most abundant element in earths crust is.
1.nitrogen
2.oxygen
3.iron
4.magnesium
The principal ore of aluminium is.
1.bauxite
2.corrundum
3.cryolite
4.Feldspar
The reason for floating of ore particles in concentration by froth floatation process is that
1.they are light
2.they are insoluble
3.they are charged
4.they are hydrophobic.
The salt which is least likely to be found in minerals is
1.sulphide
2.chloride
3.nitrate
4.None of these
The substance which is added to ore in order to remove impurities during smelting is called
1.slag
2.gangue
3.flux
4.matrix.
The wire of flash bulb is made up of
1.Cu
2.Ag
3.Mg
4.Ba.
When NaCl is dissolved in water the sodium ion is.
1.oxidised
2.reduced
3.hydrolysed
4.hydrated
Which element amongst the following has the highest boiling point?
1.Na
2.Mg
3.Ca
4.K.
Which of the following barium salts is soluble in water.
1.Barium sulphate
2.Barium carbonate
3.Barium nitrate
4.Barium phosphate
Which of the following is an ore of potassium?
1.Carnallite
2.Cryolite
3.Bauxite
4.Dolomite.
Which of the following is not an alkali metal?
1.Rb
2.Cs
3.Sb
4.Fr.
Which of the following metals can be extracted by smelting?.
1.Aluminium
2.Magnesium
3.Iron
4.Gold
Which of the following metals is always found in free state?
1.Copper
2.Mercury
3.Silver
4.Gold.
Which of the following metals is the most abundant in the earths crust?.
1.Mg
2.Na
3.Ca
4.K
Which of the following metals never occurs in free state in nature?.
1.Gold
2.Copper
3.Silver
4.Sodium
Which of the following methods is used for concentration of bauxite ore?
1.Levigation
2.Froth floatation
3.Magnetic separation
4.Leaching
Which of the following statements is correct regarding the slag obtained during the extraction of a metal like copper or iron?The slag is lighter and has lower melting point than the metalThe slag is heavier and has lower melting point than the metalThe slag is lighter and has higher melting point than the metalThe slag is heavier and has higher melting point than the metal.Which of the following statements is correct regarding the slag obtained during the extraction of a metal like copper or iron?
1.The slag is lighter and has lower melting point than the metal
2.The slag is heavier and has lower melting point than the metal
3.The slag is lighter and has higher melting point than the metal
4.The slag is heavier and has higher melting point than the metal.
Which of the following statements is correct?
1.All ores are minerals
2.All minerals are ores
3.Calcination is generally carried out in blast furnace
4.Oxide ores are concentrated by froth floatation process.
Zone refining process is used for the
1.Concentration of an ore
2.Reduction of a metal oxide
3.Purification of metals
4.Purification of an ore.