Q1. Cyanide process is used in the extraction of
Solution
Cyanide process is used in the extraction of both silver and gold because these form complex salts with CN^- ion due to presence of lone pair of electron on nitrogen atom
Cyanide process is used in the extraction of both silver and gold because these form complex salts with CN^- ion due to presence of lone pair of electron on nitrogen atom
Q2.Lapis-Lazuli’ is a blue coloured precious stone. It is mineral of the class
Solution
Lapis lazuli is the sodium alumino silicate present in earth rocks as blue stone
Lapis lazuli is the sodium alumino silicate present in earth rocks as blue stone
Q3. Which of the following statements about the advantages of roasting of sulphide ore before reduction is not true?
Solution
∆ G_f^ͦ for sulphides > ∆G_f^ͦ of CS_2 and H_2 S and thus,C and H_2 cannot reduce metal sulphide
∆ G_f^ͦ for sulphides > ∆G_f^ͦ of CS_2 and H_2 S and thus,C and H_2 cannot reduce metal sulphide
Q4. In the thermite process the reducing agent is:/span>
Solution
Al acts as strong reducing agent and converts many metal oxides (excepts I and II gp) to metals.
Al acts as strong reducing agent and converts many metal oxides (excepts I and II gp) to metals.
Q5.Which process is used for benefication of ores?
Solution
Dressing or benefication of ore involves removal of impurities from ore.
Dressing or benefication of ore involves removal of impurities from ore.
Q6. In the electrolysis of alumina, cryolite is added to:
Solution
Cryolite has these two functions during electrolysis of alumina.
Cryolite has these two functions during electrolysis of alumina.
Q7.Wulfenite (a yellow-red mineral) having waxy lustre occur in lead ores, is an important source of:
Solution
Wulfenite is a molybdate containing Pb,Mo,O_4 .
Wulfenite is a molybdate containing Pb,Mo,O_4 .
Q8.The process of Zinc –plating on iron sheet is known as
Solution
Alloys of metals with Hg are called amalgams.
Alloys of metals with Hg are called amalgams.
Q9.An essential constituent of amalgam is:
Solution
The process of zinc –plating on iron-sheet is known is known as galvanisation
The process of zinc –plating on iron-sheet is known is known as galvanisation
Q10. An ore of potassium is
Solution
B
B
