# Matter in Our Surroundings MCQ

Matter in Our Surroundings MCQ / Objective questions Chapter 1 Class 9 Science

#### What will be the volume of water in the beaker if we add one teaspoon of salt to it?

• a. Increase
• b. Decrease
• c. No change
c. No change
Explanation
Water has large intermolecular spaces. Salt molecules fill into that void, leading to no change in the volume.

#### What will happen to volume if we keep adding salt to the beaker in the above question?

• a. Increase
• b. Decrease
• c. No. change
• d. Negligible increase
a. Increase
Explanation
After continuously adding salt to the water, at the time comes when all the voids are full. Beyond this salt settle to the bottom. Beyond the addition of salt increases the volume of the beaker.

#### In which conditions solubility of a substance will increase?

• a. Increase in temperature.
• b. Increase in pressure.
• c. Decrease in temperature
• d. None
a. Increase in temperature.
Explanation
Increase in temperature and decrease in pressure increases the intermolecular distance. As a result mole solute particles can be added.

#### Heating the bottom of the steel pot filled with water heats the water at the top also. This happens due to:

• a. Conduction
• b. Convection
• d. None
b. Convection
Explanation
Bottom of the pot heats the water at the bottom. Hot water is lighter and travels to the surface. The process is termed convection.

#### Which among these will have no shape but a fixed volume

• a. An aluminum pot.
• b. An iron chisel.
• c. Mustard oil
• d. Plastic bottle
c. Mustard oil
Explanation
Liquids do not have fixed shape. They change their shape as per the surrounding. Here, mustard in a pot will acquire the shape of the pot and if filled in the bottle it will change the shape to that of a bottle.

#### Heat transfer from one terminal of a long iron rod to another is due to:

• a. Conduction
• b. Convection
• d. None
a. Conduction
Explanation
In metals free-electron oscillate and transfer energy to nearby molecule. The process is called conduction.

#### Which among these will have maximum kinetic energy?

• a. Solid
• b. Liquid
• c. Gas
• d. All have the same kinetic energy.
c. Gas

#### Heating ice converts ice into water. This energy is constant and is equal to

• a. 224 joule/gm
• b. 334 joule/gm
• c. 2230 joule/gm
• d. 2434 joule/gm
b. 334 joule/gm
Explanation
This energy is latent heat of fusion. For water it eauals to 334 joule/gm.

#### Which among these will be a more complicated mishap

• a. Burn due to spillage of hot water
• b. Spillage of boiling water
• c. Exposure of heated steam at 100ºc
• d. None
c. Exposure of heated steam
Explanation
There will be a difference equal to the latent heat of vaporization between boiling water and steam at 100 degrees Celcius. So, steam will harm more.

#### Which process causes the wind to blow?

• a. Conduction
• b. Convection
• d. None
b. Convection

#### Which among these will have the highest force of intermolecular attraction?

• a. An iron rod
• b.  100 ml of water
• c. Carbon dioxide produced by a fire extinguisher
• d. All three have an equal intermolecular force of attraction.