Tag: chemistry

Questions Related to chemistry

Which of the following increases with the increase in temperature in case of liquid?

chemistry materials liquid crystals liquid state the liquid state

  1. Surface tension

  2. Vapour pressure

  3. Viscosity

  4. Boiling point

Show answer
Correct Option: B
Explanation:
Vapour pressure increases with increase in temperature. Because, in a closed container solution contains, higher the temperature high will be the evaporation then the pressure created due to vapor i.e vapor pressure increases.
Ans :- Option B.

Which is a more volatile liquid?

chemistry materials liquid crystals liquid state the liquid state

  1. $C _{2}H _{5}OH$

  2. $CH _{3}COOH$

  3. $C _{2}H _{5}OC _{2}H _{5}$

  4. $C _{6}H _{6}$

Show answer
Correct Option: D
Explanation:

Presence of hydrogen bonding in a liquid decreases its volatile nature. This is because due to hydrogen bonding, there is more association between the molecules and the tendency to go into gaseous phase decreases. Hence, $C _6H _6$ will be more volatile liquid since it has no hydrogen bonding.

$510 mg$ of a liquid on vaporization in victor Mayer's apparatus displaces $67.2 ml$ of dry air (at NTP). The molecular weight of liquid is:

chemistry materials liquid crystals liquid state the liquid state

  1. $130$

  2. $17$

  3. $1700$

  4. $170$

Show answer
Correct Option: B
Explanation:

As we know that $1g$ mole of any gas occupies as $22400ml$ of volume at STP

So molecular mass of compound= $\cfrac {0.510\times 22400}{67.2}$
$\Rightarrow 16.999 \approx 17$

When a student was given aviscometer, the liquid was sucked with difficulty, the liquid may be:

chemistry materials liquid crystals liquid state the liquid state

  1. benzene

  2. toluene

  3. water

  4. glycerine

Show answer
Correct Option: D
Explanation:

Among the given liquid glycerine is a viscous liquid and hence it was sucked with difficulty.

How many of the following properties are shown by liquid  state?
Rigidity, Definite volume. No free surface, Define shape

chemistry materials liquid crystals liquid state the liquid state

  1. $1$

  2. $2$

  3. $3$

  4. $4$

Show answer
Correct Option: A
Explanation:

The properties of liquids are as follows:

  • It does not have a fixed shape but it has a fixed volume.
  • It does not have definite shape.
  • It has a free surface.
  • It does not show rigidity.

The temperature remains constant during melting and all the ice changes into water. The enthalpy change associated with this process is due to _____________.

chemistry materials liquid crystals liquid state the liquid state

  1. latent heat of fusion

  2. latent heat of vaporisation

  3. latent heat of evaporation

  4. latent heat of sublimation

Show answer
Correct Option: A
Explanation:

Latent heat is the energy released or absorbed by a body during a constant temperature process. An example is a phase transition such as ice melting or water boiling. Heat absorbed during melting is called latent heat fusion.

Can water be made to boil in a paper cup without the paper being burnt. This is because ___________.

chemistry materials liquid crystals liquid state the liquid state

  1. temperature of water does not change during boiling.

  2. ignition temperature of paper is higher than the boiling point of water

  3. high latent heat of vaporization of water

  4. All the above

Show answer
Correct Option: D
Explanation:

The paper cup in which water is placed is having ignition temperature higher than the  boiling point of water, and water have high latent heat of vaporization. This is also possible that temperature provided to water does not exceed its boiling point. Hence, water can boil in paper cup without burning the cup.

Why does temperature remain constant as a liquid is heated and gets converted to its gaseous state at its boiling point? 

chemistry materials liquid crystals liquid state the liquid state

  1. Due to increase in potential energy

  2. Due to increase in kinetic energy 

  3. Due to decrease in potential energy

  4. Due to decrease in kinetic energy

Show answer
Correct Option: B
Explanation:

As a liquid is heated at constant pressure, its temperature increases. This trend continues until the boiling point of the liquid is reached. No further rise in temperature of the liquid can be induced by heating due to increase in kinetic energy.

Which one of the following is a correct statement?
1. Ice provides more cooling effect than water at $273\ K$.
2. Evaporation of a liquid causes cooling.
3. Increase of pressure lowers the separation between the particles of matter.

chemistry materials liquid crystals liquid state the liquid state

  1. $1$ and $2$

  2. $1$ and $3$

  3. $2$ and $3$

  4. $1, 2$ and $3$

Show answer
Correct Option: D
Explanation:

Ice provides more cooling effect than water at 273 K because of latent heat of fusion. Evaporation of a liquid causes cooling as the surface molecules take away heat to escape out. Increase of pressure lowers the separation between the particles of matter and brings them closer leading to change of state from gas to liquid and to solid.

The best evidence for the existence and movement of particles in liquids was provided by ______________.

chemistry materials liquid crystals liquid state the liquid state

  1. John Dalton

  2. Thomas Edison

  3. J.J. Thomson

  4. Robert Brown

Show answer
Correct Option: D
Explanation:

Robert brown observed a weak solution of milk and later pollen grains in suspension with a high-powered microscope, and saw that the particles of milk and the pollen grains showed a violent and random motion. This motion was named as Browninan motion.