Chemistry · Science General

States of Matter

2,682 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 biology aids to health immunization, treatment and antibiotics antibodies and antitoxin prevention and treatment of disease

Deodorants are

  1. Both antiseptic and disinfectant

  2. Only disinfectant

  3. Neither antiseptic nor disinfectant

  4. Only antiseptic
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

These are strong chemical substances that are applied on spots and places where germs thrive an multiply and places where germs thrive and multiply.commonly used disinfectants are cresol, phenol, Lysol,40% formalin, lime, Bordeaux mixture, DDT etc. Precaution-all disinfectants are strong and should not come in contact with the human skin Strong heat and boiling also destroy germs and may be called physical disinfectants.deodorants are neither antiseptics nor disinfectants.they only serve to mask a bad smell.
So, the correct answer is  'Neither antiseptic nor disinfectant'.
Multiple choice

What is H2O?

  1. water

  2. gasoline

  3. milk

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

H2O is the chemical formula for water, consisting of two hydrogen atoms and one oxygen atom. The other options are not represented by this formula.

Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

An organic liquid vaporizes at a temperature _________ its boiling point in steam distillation.

  1. above

  2. below

  3. equal to

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

In steam distillation, the mixture boils when the sum of vapour pressures of water and the organic liquid becomes equal to the atmospheric pressure. Since the vapour pressure of water is appreciably higher than that of the organic liquid, it vaporizes at a temperature much lower than its normal boiling point. 

In this way, many organic compounds insoluble in water can be purified at a temperature well below the point at which decomposition occurs. 

Multiple choice physics observing space: telescopes maxwell's equations the nature of light introduction to electromagnetic waves

Identify the medium required for Electromagnetic waves to travel?

  1. none

  2. liquid

  3. solid

  4. gas

  5. fluid (liquid or gas)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Electromagnetic wave does not require any material medium to propagate. These can also travel through vacuum. Also EM waves travel with the speed equal to that of light  i.e $3 \times 10^8$ m/s

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

Give an example of each of the following chemical changes: An endothermic reaction 

  1. making ice cubes

  2. condensation of rain from water vapor

  3. baking bread

  4. mixing sodium sulfite and bleach
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Exothermic reactions are reactions or processes that release energy, usually in the form of heat or light. In an exothermic reaction, energy is released because the total energy of the products is less than the total energy of the reactants.
When quick lime reacts with water to form slaked lime , it releases a lot of energy . 
Endothermic reactions are reactions that require external energy, usually in the form of heat, for the reaction to proceed. Since endothermic reactions draw in heat from their surroundings, they tend to cause their environments to cool down. They are also generally non-spontaneous, since endothermic reactions yield products that are higher in energy than the reactants. 
When hydrogen reacts with iodine to form hydrogen iodide , it absorbs a lot of energy .

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

If you, pour a few drops of petrol on your palm, it will feel cool as the petrol evaporates. This change is a/an:

  1. endothermic reaction

  2. exothermic reaction

  3. chemical reaction

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

Evaporation is a process that requires energy (latent heat of vaporization) to turn a liquid into a gas. Because the petrol absorbs heat from the palm to evaporate, the palm feels cool, which is an endothermic process.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

Which of the following are exothermic processes?
(A) Reaction of water with quick lime
(B) Dilution of an acid
(C) Evaporation of water
(D) Sublimation of Camphor (Crystals)

  1. (a) and (b)

  2. (b) and (c)

  3. (a) and (d)

  4. (c) and (d)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Addition of quick lime to water and dilution of acid are examples of exothermic reactions.
The addition of quick lime (CaO) to water gives a hissing sound and is known as slaking of lime. It is an exothermic reaction with release of 15000 cal/mol
$CaO + H _2O \rightarrow Ca(OH) _2 + 15000  : cal$
Conc sulfuric acid has very high affinity for water. When sulfuric acid is mixed with water, a large amount of hat is released. The temperature may rise to as high as $120^o  : C$.
Hence, sulfuric acid is always diluted by adding acid to water.
On the other hand, evaporation of water and sublimation of Camphor are endothermic processes.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

Which of the following reaction is not endothermic in nature?

  1. breaking of bonds

  2. digestion of food

  3. combustion of Carbon

  4. evaporation of water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Combustion or burning is a high temperature exothermic redox chemical reaction between fuel and an oxidant oxygen. Evaporation and sublimation are phase change physical process of water. Digestion of food is breakdown of larger molecules into small ones by bong breaking which is an endothermic process.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

Which of the following is an exothermic process?

  1. Dilution of sulphuric acid

  2. Sublimation of dry ice

  3. Evaporation of water

  4. Melting of ice
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A large amount of heat is released because the hydration reaction of sulfuric acid is highly exothermic and dilution should always be performed by adding the acid to the water rather than the water to acid. As hydration of sulfuric acid is thermodynamically favorable and the affinity of it for water is sufficiently strong.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

If you pour a few drops of petrol on your palm, it will feel cool as the petrol evaporates. This change a/an:

  1. endothermic reaction

  2. exothermic reaction

  3. chemical reaction

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

If you pour a few drops of petrol on your palm.it will feel cool as the petrol evaporates this is a endothermic reaction.Because petrol is very volatile in nature, so when it evaporates.it absorb heat energy from the surroundings.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

During the dissolution of urea, heat:

  1. is absorbed

  2. is evolved

  3. does not change

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

During the dissolution of urea, heat is absorbed the term,dissolution,refers to a solute dissolving in a solvent to form a solution.In this experiment the solute is  solid urea.Urea being a molecular substance,does not dissociate into ions.The dissolution process involves adding energy to break the attractive forces between the molecules in the solid structure and releasing energy as the molecules form new attractive forces with the water molecules sourrounding it.

Multiple choice chemistry endothermic and exothermic reactions endothermic reactions what are enthalpy changes energy change in chemical reactions

Which of the following are endothermic process?

  1. boiling of water

  2. dissolving salts in water
  3. dissolving conc. $H _2SO _4$ in water

  4. evaporation of water
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation
  1. Boiling of water would be an endothermic process because the system (water) is absorbing heat to turn into vapour. Hence both option 1 $ 3 are endothermic.
     And the reverse process would therefore be exothermic.

    2. Addition of Conc. acids to water is an exothermic reaction.