CIE Chemistry Paper-1: Specimen Questions 65 - 67 of 99
Question number: 65
The process in which an ore is heated to a high temperature In the absence of air is known as:
Calcination is the process in which an ore is heated to a high temperature In the absence of air. Usually carbonate ores or ores containing water are calcined to drive out carbon and moisture impurities.
Question number: 66
Which of the following sentences are false about metals?
- Metals have high density and melting point
- All metals are solid In state
- Metals are not ductile.
- Metals are generally shiny
2) and 3)
3) and 4)
Following are the properties of a metal:
- Metals are described as malleable (can be beaten into sheets) and ductile (can be pulled out into wires). This is because of the ability of the atoms to roll over each other into new positions without breaking the metallic bond.
- All metals are not solid. Mercury is a metal, which is liquid at room temperature.
Question number: 67
The process of rusting happens by which of the following reasons:
Presence of air
Presence of water
|c.||Both a. and b. are correct|
|d.||Question does not provide sufficient data or is vague|
Rust is an iron oxide, usually red oxide formed by the redox reaction of iron and oxygen in the presence of water or air moisture. Rusting is the common term for corrosion of iron and its alloys, such as steel. Many other metals undergo equivalent corrosion, but the resulting oxides are not commonly called rust.