Chemical Industry Multiple Choice Questions on “Copper”.
1. Which among the following is an ore of copper?
a) Hematite
b) Magnetite
c) Chalcopyrite
d) Siderite
Answer: c
Clarification: The predominant ore of copper is chalcopyrite (CuFeS2). Hematite, magnetite and siderite are ores of iron.
2. Which method is used to extract copper from sulphide ores?
a) Froth floatation
b) Leaching
c) Screening
d) Mechanical agitation
Answer: a
Clarification: In froth floatation process, the ore is added to water and other reagents and is mechanically agitated forming bubbles. As the bubble rises it carries the copper along.
3. What are the steps involved in purifying copper? (In order of precedence)
a) Smelting-Roasting-Converting
b) Smelting-Converting-Roasting
c) Converting-Roasting-Smelting
d) Roasting-Smelting-Converting
Answer: d
Clarification: Water is first removed by roasting. Steamed air is sent in to remove the volatile impurities. The final is conversion of matte.