Tag: chemistry

Questions Related to chemistry

Which method is used to get pure ethanol?

chemistry carbon and its compounds some important carbon compounds ethanol and ethanoic acid introduction to alcohols - ethanol

  1. Membrane technology

  2. Esterification

  3. Fermentation

  4. None of these

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Correct Option: D
Explanation:

In industrial method, to obtain 100% pure alcohol, a small quantity of benzene is added to rectified spirit and the mixture is then distilled. Absolute alcohol is obtained in third fraction that distills over at 78.2°C (351.3 K).

None of the given method is correct. 

Option D is the answer.



A gaseous oxide contains 30.4% of nitrogen, one molecule of which contains one nitrogen atom. The density of the oxide relative to oxygen is:

chemistry chemical formula and mole concept introduction to mole gas laws and mole concept mole concept

  1. 0.94

  2. 1.44

  3. 1.50

  4. 3.0

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Correct Option: B
Explanation:

100g of oxide contain 30.4 g of Nitrogen. 


Since 1 molecule contain one nitrogen atom

14 g Nitrogen is contained by Mol. wt of oxide.

30.4 g of nitrogen present in 100 g of oxide 

$ 1 g ------------\dfrac{100}{30.4} $

$ 14 g-------------\dfrac{100 \times 14}{30.4} $

$ \dfrac{doxide}{doxygen}=\dfrac{Moxide}{Moxygen}=\dfrac{\dfrac{1400}{30.4}}{32}=1.44 $

Suspension is a heterogeneous mixture in which very fine particles of a solid are dispersed in any medium (liquid or gas). Fine particles of the solid remain suspended in the medium.

chemistry composition of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. True

  2. False

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Correct Option: A
Explanation:

A suspension is a heterogeneous mixture in which very fine particles of a solid are dispersed in any medium (liquid or gas). Fine particles of the solid remain suspended in the medium.

Following are the characteristics properties of suspensions

i) Heterogeneous nature: a suspension is a heterogeneous system.

ii) Visibility: the particles in a suspension can be seen with naked eyes or under a simple microscope.

iii) Particle Size: in a suspension, the size of the particles is of the order of 10-7 make or larger.

iv) Sedimentation: the particles in a suspension travel tendency to settle down. Very fine particles, however, remain suspended in the medium.

v) Separation by filtration: Larger particles in a suspension can be separated from the liquid or air by the filtration. 

A teacher instructed four students $A, S, C$ and $D$ to prepare a suspension of chalk in water. The students prepared suspension in the following manner:
student $'A'$ places a piece of chalk in water.
student $'S'$ places powdered chalk in water.
student $'C'$ places powdered chalk in water and then shakes the mixture vigorously.
student $'D'$ places powdered chalk in dil. $HCl$.
Which of the following students has correct way of preparation of suspension?

chemistry nature of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. Student A

  2. Student B

  3. Student C

  4. Student D

Show answer
Correct Option: C
Explanation:

The correct option is (c).
On dissolving chalk powder in water,a suspension is obtained.The mixture is stirred for sometime to ensure the uniform dispersion of chalk powder in water.
Suspension is a heterogeneous mixture of particles from which the particles are settled down with time.Chalk powder does not dissolve in water at all.It just forms suspension in water and after some time settles down under the influence of gravity. 

Suspensions have solute particles with size less than 1 nm.

chemistry composition of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. True

  2. False

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Correct Option: B
Explanation:

True solutions have solute particles with size less than 1 nm whereas suspensions have size more than 100 nm.
Colloids have size between 1 to 100 nm.

Suspension is a non-homogeneous mixture in which very fine particles of .................. are dispersed in .................

chemistry nature of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. solid/liquid, gas/solid

  2. gas, liquid

  3. solid, liquid/gas

  4. solid/liquid/gas, liquid

Show answer
Correct Option: C
Explanation:

A suspension is a heterogeneous mixture in which very fine particles of a solid dispersed in any medium (liquid/gas). In any suspension, fine particles of the solid remain suspended in the medium.

Muddy pond water and smoke is an example of a:

chemistry nature of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. colloid

  2. suspension

  3. true solution

  4. none of the above

Show answer
Correct Option: B
Explanation:

A suspension is a heterogeneous mixture in which very fine particles (about 10-5m in size) of solid are dispersed in any medium (liquid or gas). In suspension, the solute particles are visible to the naked eye, and remain suspended throughout the bulk of the medium. The Tyndall effect is observed in this mixture.

Muddy pond water, smoke coming out of a chimney, chalk-water mixture, coarse lime particles in water are examples of suspension.

_______________ contains solid particles that are sufficiently large for sedimentation.

chemistry nature of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. Pure substance

  2. Element

  3. Suspension

  4. Solution

Show answer
Correct Option: C
Explanation:

A suspension is a heterogeneous mixture containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than one micrometer.

Suspensions are different from colloid because :

chemistry composition of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. the particles of suspension settle

  2. the particles of suspension do not settle

  3. solvent and solute of suspension are homogenously moxed

  4. both a and c

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Correct Option: A
Explanation:

Unlike colloids, suspensions will eventually settle. The suspended particles are visible under a microscope and will settle over time if left undisturbed. This distinguishes a suspension from a colloid, in which the suspended particles are smaller and do not settle. Colloids and suspensions are different from solutions, in which the solvent and solute are homogeneously mixed.

If a liquid is suspended in another liquid, it is called :

chemistry nature of matter heterogeneous mixture - suspension and its properties suspension types of mixture

  1. emulsion

  2. aerosol

  3. colloid

  4. particulate

Show answer
Correct Option: A
Explanation:

Putting two or more liquids together creates an emulsion if the liquids do not mix. If a liquid is suspended in another liquid, it is called an emulsion.