ICSE ICSE Class 8 - CISCE Question Bank Solutions

Colloids have the particle size range between

Explain the term of  Solute.

Explain the term of solvent.

Explain how the following factor affects the formation of a solution is proportion of the solute & the solvent.

Explain how the following factor affects the formation of a solution is particle size of the solute.

Explain how the following factor affects the formation of a solution is Temperature of the solvent.

Define the term ‘solubility ’ of a solute in water. If 10 g. of a solute is added to 100 g. of water at 50°C and stirred, it is seen that the total solute dissolves at that temperature giving an unsaturated solution. Is 10 g, the solubility of the solute in water. Give reasons.

Give a reason why on opening a bottle of soda [carbon dioxide dissolved in water] the gas escapes out with a ‘fizz’.

How are solutions generally classified. What is the basis of this classification.

Draw a table to differentiate – True solutions, colloidal solutions & suspensions – with respect to

1. Type of mixture
2. Solute particles in the mixture.

Give four examples of each of the above types of solutions i.e. true solution, colloidal solution & suspension. Give a reason why a true solution does not exhibit ‘Tyndall effect’.

Select the correct answer of the following statement:

A heterogenous mixture of undissolved particles in dispersion medium, visible to the naked eye.

Complete the statement by filling the blank with the correct word from the option.

Solubility of a solute is the _______ amount of solute that will saturate 100 g. of water at t°C.

Give reason for the following:

All solutions are homogenous mixtures of a solute in a solvent.

Give reason for the following:

Colloidal solutions exhibit brownian movement.

A chemical reaction may be ‘reversible’ in nature. State the meaning of the term in italics.

Give a reason why a catalyst is used in certain chemical reactions.

Give a balanced equation for the reversible catalytic reaction involving sulphur dioxide as one of the reactants.

Certain thermal decomposition reaction, resulting in the formation of the oxide. Give a balanced equation for the thermal decomposition of the following, which result in the formation of metallic oxide.

Limestone
\[\ce{CaCO3->[\Delta]CaO + CO2}\]

Certain thermal decomposition reaction, resulting in the formation of the oxide. Give a balanced equation for the thermal decomposition of the following, which result in the formation of metallic oxide.

Lead carbonate
\[\ce{PbCO3->[\Delta]PbO + CO2}\]