Chemistry · Science General

States of Matter

2,382 Questions

States of matter questions explore physical changes, evaporation, phase transitions, and the properties of liquids and gases. Topics cover density, cryosurgery, heavy water, and electrolytes. This foundational chemistry topic frequently appears in general science sections of SSC and railway exams.

Phase change mechanismsEvaporation and temperature effectsProperties of liquidsPhysical versus chemical changesElectrolytes and heavy water

States of Matter Questions

Multiple choice fluid dynamics option b: engineering physics physics

Hot syrup flows faster because:

  1. Surface tension increases when temperature is increased.

  2. Viscosity decreases when temperature is increased.

  3. Viscosity increases when temperature is increased.

  4. Surface tension decreases when temperature is increased.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hot syrup is liquid at higher temperature. We know that as temperature increases viscosity decreases for liquids. So, hot syrup flows faster as viscosity decreases.

Multiple choice fluid dynamics option b: engineering physics physics

With increase in temperature, the viscosity of:

  1. gases decreases and liquid increases

  2. gases increases and liquid decreases

  3. both gases and liquid increases

  4. both gases and liquid decreases
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The viscosity of liquid is inversely proporional to the square of the temperature, therefore as we increase the temperature, the viscosity of liquids will decrease.


Similarly, the viscosity of gases is linearly proportional to the temperature. hence as the temperature increases, the viscosity will increase

Multiple choice fluid dynamics option b: engineering physics physics

A good lubricant should be highly

  1. viscous and velocity

  2. non-viscous volatile

  3. viscous and non-volatile

  4. transparent
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A good lubricant generally possesses the following characteristics: A high boiling point and low freezing point (in order to stay liquid within a wide range of temperatures) A high viscosity index. Thermal stability.

Multiple choice fluid dynamics option b: engineering physics physics

More viscous oil is used in summer than in winter in motors due to

  1. rise in temperature in summer, the viscosity of oil increases.

  2. rise in temperature in summer, the viscosity of oil decreases.

  3. surface tension of oil decreases.

  4. surface tension of oil increases.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Due to rise in temperature viscosity of oil decreases in summers. So more viscous oils are used for better lubricant protection.

Multiple choice fluid dynamics option b: engineering physics physics

With the increasing molecular mass of a liquid, the viscosity .

  1. decreases

  2. increases

  3. no effect

  4. all wrong
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

With the increasing molecular mass of a liquid, the viscosity increases.
The flow of molecules is inversely proportional to its mass. Hence, liquids with high molecular mass possess greater viscosity.

Multiple choice chemistry introduction to analytical chemistry interpreting a balanced chemical reaction percentage yield stoichiometric calculations
Statement (A):The constant temperature at which a solid change into liquid state by absorbing heat energy is called melting point.
Statement (B): The constant temperature at which a liquid changes into gaseous state by absorbing heat energy is called point.
Statement (C): The melting and boiling points of a pure substance is always a constant and is a good measure of finding the purity of the substance.

  1. All the statement are correct

  2. All the statement are incorrect

  3. A, B are correct and C is incorrect

  4. A, B are incorrect and C is correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$A\rightarrow $ Its defination of melting point.

$B\rightarrow $ Its defination of boiling point. 
$C\rightarrow $ Pure substance have constant boiling and melting point. 
$\therefore $ All are true.

Multiple choice chemistry introduction to analytical chemistry interpreting a balanced chemical reaction percentage yield stoichiometric calculations

Which of the following is not the criterion of purity of a substance?

  1. Solubility

  2. Melting point

  3. Boiling point

  4. Density
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

A pure substance shows a sharp melting point & boiling point. Hence melting point & boiling point determines the purity.

But density & solubility are not the criterion of purity of substance.

Multiple choice chemistry changes around us crystallisation process of separating components of a mixture physical changes

What is a chemical change?

  1. Change in size, shape

  2. Change from one substance to another new substance

  3. Change in temperature from lower to higher

  4. None of above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A chemical change is a process where one or more substances are converted into one or more new substances. Examples: Explosion of fireworks that produces heat, light, sound and unpleasant gases, breaking down of ozone in the ozone layer by the UV radiations.


Hence, the correct option is $B$

Multiple choice chemistry changes around us crystallisation process of separating components of a mixture physical changes
An example of chemical change is :

  1. water condensing on the outside of your cold beverage

  2. bending a wire

  3. slicing bread

  4. freezing water

  5. burning a candle
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Burning of candle is a chemical change because the wax gets converted into carbon dioxide whereas the rest of the options represent the physical change.


Hence the correct option is E.

Multiple choice chemistry changes around us crystallisation process of separating components of a mixture physical changes

While forming crystals, it is important to :

  1. evaporate to dryness to get purest possible crystals

  2. attach gas syringes to collect fumes

  3. not evaporate water of crystallization

  4. use high flames
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Crystals contain water of crystallization hence during formation of crystals water of crystallization should not be evaporated.

Also, crystallization is the process of formation of crystals. Crystals is defined as the highly organized molecule into a well-known structure.

Multiple choice chemistry changes around us crystallisation process of separating components of a mixture physical changes

Which of the following is not a feature of chemical change?


(I) Original substance can be obtained by simple physical methods.
(II) It is a temporary change.
(III) The new substances formed have properties different from those of the reacting substances.

  1. I, II

  2. I, III

  3. II, III

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

One more new substances one formed in a chemical change. The new substances formed have properties different from those of the reacting substances. A chemical change is always accompanied by the absorption or evolution of energy in the form of heat, light or sound.