Which statement is correct?

• Cu reacts with steam to liberate hydrogen

• Magnesium is more reactive than calcium

• Potassium reacts with water to form hydrogen gas

• Sodium oxide can be reduced by carbon to form sodium

Which substances do not react together?

• Zinc and dilute HCl

• Cu and dilute HCl

• Na and water

• Ca and water

Oxide of element X can be reduced by carbon. But element X does not react with steam or dilute HCl . What is X?

• Cu

• Mg

• Zn

• Fe

Potassium nitrate decomposes to form potassium nitrite and ....................................gas

Lithium nitrate decomposes to form which gas?

• Oxygen

• Nitrogen

• Nitrogen di oxide

• Water vapor

Zinc blend is heated in oxygen to form

• Zinc sulphide

• Carbon

• Zinc oxide and carbon di oxide

• Sulphur di oxide and zinc oxide

The compound used to remove silica from blast furnace in extraction of iron is

• SiO2

• CaSiO3

• CaCO3 or Lime stone

• oxygen

Aluminium is used to make aircraft bodies as it is

• Soft

• Lightweight and strong

• Unreactive oxide layer

• Has high density

Brass is an alloy of

• 70% Zn and 30% Cu

• 60% Zn and 40% Cu

• 70% Cu and 30% Zn

• 40% Sn and 60% Cu

Steel making occurs in BOC which is