Tag: materials

Questions Related to materials

A liquid cannot be compressed because it has a fixed volume.

chemistry materials liquid crystals liquid state the liquid state

  1. True

  2. False

  3. Either

  4. Neither

Show answer
Correct Option: A
Explanation:

1) A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure.

2) When you compress liquid together, the molecular forces  become very strong stopping it from being compressed very much.

Hydrogen was collected in one case over water, and in another over mercury in the same conditions. In both cases, the volume of the gas was the same.
Amounts of hydrogen collected over?

chemistry materials liquid crystals liquid state the liquid state

  1. Both liquids were identical

  2. The water was greater

  3. The mercury was greater

  4. Noting can be predicted from the given data

Show answer
Correct Option: C

Which liquid has maximum surface tension?

chemistry materials liquid crystals liquid state the liquid state

  1. Water

  2. Alcohol

  3. Ammonia

  4. Glycerol

Show answer
Correct Option: A
Explanation:
Tension of the surface film of a liquid caused by attraction of the particles in the surface layer by the bulk of the liquid which minimize surface area.
$\bullet $  Water $=72.86$ $nN/m$
$\bullet$  Ethanol (Alcohol) $=22.10$ $nN/m$
$\bullet$  Glycerol $=64.00$ $nN/m$
Ans :- Option A

When ethanol mixes in cyclohexane reduces the intermolecular forces between ethanol molecule. In this, liquid pair shows:

chemistry materials liquid crystals liquid state the liquid state

  1. ${ \Delta H } _{ mix }>0$

  2. ${ \Delta V } _{ mix }<0$

  3. ${ \Delta G } _{ mix }<0$

  4. ${ \Delta H } _{ mix }=0$

Show answer
Correct Option: A
Explanation:
On adding cyclohexane to ethanol . Its molecules get in between the molecules of ethanol thus breaking the hydrogen bonds and reducing ethanol - ethanol interaction .
Thus will increase the vapour pressure of the solution and result in positive deviation from Rouault's law.

With increase in temperature, the fluidity of liquids 

chemistry materials liquid crystals liquid state the liquid state

  1. increases

  2. decreases

  3. remains constant

  4. may increase or decrease

Show answer
Correct Option: A

A liquid of density $1.07\ g/ml$ is filled in the barometer, in place of mercury. What should be the length of liquid column, if another barometer filled with mercury, is measuring $75\ cm$ pressure?

chemistry materials liquid crystals liquid state the liquid state

  1. $75\ cm$

  2. $600\ cm$

  3. $9.375\ cm$

  4. $6000\ cm$

Show answer
Correct Option: B

A beaker is filled with a liquid of density $\rho $ upto a height pressure on the walls is :

chemistry materials liquid crystals liquid state the liquid state

  1. 0

  2. $h \rho g $

  3. $h \rho g/2 $

  4. $2 h \rho g $

Show answer
Correct Option: C

The latent heat of vaporisation of water is:

chemistry materials liquid crystals liquid state the liquid state

  1. $2.25\times 10^6 J/kg$

  2. $2.25\times 10^8 J/kg$

  3. $2.25\times 10^4 J/kg$

  4. $2.25\times 10^{-6} J/kg$

Show answer
Correct Option: A
Explanation:

The heat of fusion for water at 0 °C is approximately 334 joules (79.7 calories) per gram, and the heat of vaporization at 100 °C is about 2,250 joules (533 calories) per gram or $2.25 *10^6$ J/kg.

The boiling point of a liquid with the increase of pressure,  ______________.

chemistry materials liquid crystals liquid state the liquid state

  1. decreases

  2. increases

  3. remains constant

  4. changes according to the weather

Show answer
Correct Option: B
Explanation:

Since a liquid vaporises when molecules moves faster and farther apart but while increasing pressure, we apply an external force to hold molecules closer to each other. Hence, molecules will require more energy to overcome this resistance thus this increases boiling point of liquid. Hence, the boiling point of a liquid with the increase of pressure, increases.

Which tool allows liquids to be swirled with a low risk of spilling?

chemistry materials liquid crystals liquid state the liquid state

  1. Crucible

  2. Evaporating dish

  3. Tonds

  4. Erlenmeyer flask

  5. Mortar and pestle

Show answer
Correct Option: D
Explanation:

Erlenmeyer flask $\rightarrow$ 

It is used as a container for liquids. Its Shape makes it easy and safe to swirl liquids without spilling, making them ideal for titration. It cannot be used to measure the volume of liquid because its shape makes it difficult to make accurate readings.
Hence the required answer is (C) Erlenmeyer flask.