Question

Q4) What is 'Water of crystallization'? Give two examples.
QS) What happens when copper sulphate crystals are heated? Give
chemical equation.
Q6) What is the cause of formation of acidic, basic and neutral oxide?
Q7) 'A white coloured compound is used for plastering fractured
bones.'Name the white coloured compound. How is it prepared? Give
chemical equation. Give any of its two other uses.
98) What happens when P.O.P is added to water? Give chemical
equation.
09) What is the cause of tooth decay?
Q10) Give a test for the presence of carbon dioxide gas.


please solve it​

Answer 1

Explanation:

What is 'water of crystallisation' ? Give two examples.

Answer -

The water molecules which form part of the structure of a crystal (of a salt) are called water of crystallisation. The salts which contain water of crystallisation are called hydrated salts.

Examples :-

Copper sulphate(CuSO4.5H2O), Iron sulphate(FeSO4.7H2O)

What happens when Copper sulphate crystal are heated ? Give chemical equation.

Answer -

when copper sulphate crystal are heated then blue copper sulphate crystals turn white due to the loss of water of crystallisation.

Chemical equation -

CuSO4.5H2O ---Heat---> CuSO4 + 5H2O

What is the cause of formation of acidic, basic and neutral oxide ?

Answer -

Acidic oxide forms when non-metal reacts with oxygen.

Basic oxide forms when metal reacts with oxygen

'A white coloured compound is used for plastering fractured bones.' Name the white coloured compound. How is it prepared ? Give chemical equation. Give any of its two other uses.

Answer -

The white coloured compound is plaster of Paris.

Preparation :-

When Gypsum is heated to a temperature of 100°C, it loses three-forths of its water of crystallisation and form plaster of Paris.

Chemical equation -

CaSO4.2H2O --100°C--> CaSO4. ½H2O + 3/2H2O

Uses :-

• Plaster of Paris is used in hospitals.
• Plaster of Paris is used in making toys.
• Plaster of Paris is used as fire-proofing material.
• Plaster of Paris is used for making surfaces smooth before painting.

What happen when POP is added to water ? Give chemical equation.

Answer -

When water added to plaster of Paris then it forms gypsum, this is why plaster of Paris should be stored in a moisture proof container.

Chemical equation -

CaSO4.½H2O + 3/2H2O -> CaSO4.2H2O

What is the cause of tooth decay ?

Answer -

When we eat food containing sugar, then the bacteria present in our mouth break down the sugar to form acid. Thus, acid is formed in the mouth after a sugary food has been eaten. This acid lowers the pH in the mouth and tooth decay started.

Give a test for the presence of carbon dioxide gas.

Answer -

For the presence of carbon dioxide gas :-

Step 1 :-

Take a boiling tube and put sodium carbonate in it.

Step 2 :-

Add dilute hydrochloric acid in the boiling tube.

Step 3 :-

we will observe the brisk effervescence of a gas is produced.

Step 4 :-

Pass the gas through lime water

Step 5 :-

we will observe that lime water turns milky showing that it is carbon dioxide gas.