Chemical Substances and Processes

The chemical formula of Calcium Chloride is-

• CaCl₂

• Ca₂Cl

• CaCl

• None

Which of the following is not a pure substance?

• Iron

• Rain water

• Air

• Oxygen gas

The symbol of carbonate ion is -

• CO₃

• CO₃^-2

• CO₂^-3

• CO₃²⁺

When iron rod is dipped in copper sulphate solution the following observations can be observed-

• The change of colour of solution from red to blue and brown coating on iron nail

• The change of colour of solution from green to blue and grey coating on iron nail.

• The change of colour of solution from blue to green and brown coating on iron nail

• The change of colour of solution from blue to green and black coating on iron nail

Which of the following is not a chemical change?

• Photosynthesis

• Digestion of food

• Respiration in plants and animals

• Breaking of glass

The products of Neutralisation reaction are-

• Acid, water

• Base, salt

• Base, water

• Salt, water

Fe (s) + CuSO₄ -> FeSO₄ + Cu. This is _____ reaction.

• Addition reaction

• Displacement reaction

• Decomposition reaction

• Neutralisation reaction

Iron get rusted in coming in contact with-

• Air and soil

• Water and sunlight

• Oxygen and animals

• Air and moisture

The chemical formula of sodium is.

• So

• No

• Na

• Sd

Equation having same no. of atoms of each element on both the sides is called-

• Chemical equation

• Chemical reaction

• Balanced chemical equation

• Chemical formula