Tag: chemistry

Questions Related to chemistry

The constituents of the mixture are easily seen with naked eyes. Then the mixture is ____________.

  1. Homogenous

  2. Heterogenous

  3. Both (a) and (b)

  4. None of these

Correct Option: B

The homogenous mixture consists of different components which are uniformly distributed in the solution and it can't be seen with naked eyes.

The heterogeneous mixture consists of two or more parts which have different compositions. These have visible boundaries of separation between the different constituents and can be easily seen even with naked eyes.

When sunlight passes through the window of a classroom, its path is visible. This is due to ________ of light. 

  1. reflection

  2. scattering

  3. saturation

  4. absorption

Correct Option: B

Due to Tyndall effect, there occurs scattering of light and the path becomes visible. The dust particles scatter the beam of light.

Which of the following statement(s) is\are not correct?

  1. $\text{An element of a substance contains only one kind of atom}$

  2. $\text{A mixture is not always heterogeneous}$

  3. $\text{Elements can exist as atoms or molecules but compounds exist only as molecules}$

  4. $\text{Atoms of same element have always same atomic mass number}$

Correct Option: D

Atoms of the same element can have different mass numbers and they are known as isotopes.

For example,

Hydrogen have $3$ isotopes.
$H_1^1, \ D_1^2, \ T_1^3$

Hence, option $D$ is an incorrect statement.

The example of heterogeneous mixture is:

  1. Water and stone.

  2. Water and lemon juice.

  3. Water and alcohol.

  4. Water and sugar.

Correct Option: A

A heterogeneous mixture is simply any mixture that is not uniform in composition. Two immiscible liquids form heterogeneous mixtures.

In given examples, water & lemon juice, water & alcohol, water & sugar result in uniform composition forming homogeneous mixture.
$\therefore$ Water and stone is a heterogeneous mixture.

A mixture of $100mL$ of $CO,CO_2$ and $O_2$ was sparked. When the resulting gaseous mixture was passed through $KOH$ solution, concentration in volume decrease by $80mL$,. the composition of initla mixture may be (in the same order).
(a) $30mL,60mL,10mL$ (b) $30mL,50mL,20mL$ (c) $50mL,30mL,20mL$ (d) $20mL,70mL,10mL$

  1. a and c

  2. a and b

  3. b and d

  4. c and d

Correct Option: B

Molecules is the smallest particle of _______________

  1. compound

  2. substance

  3. mixture

  4. element

Correct Option: C

Two solid mixtures are :

  1. steel.

  2. solder.

  3. phosphor bronze.

  4. all of these.

Correct Option: D

All of them are alloys. Alloy is a material which is composed by mixing two or more metals or a metal and a non-metal. An alloy may be a solid solution of the elements (a single phase), a mixture of metallic phases (two or more solutions) or an intermetallic compound with no distinct boundary between the phases.
Examples of alloys are steel, solder, brass, pewter, phosphor bronze and an amalgam.

The separation of mixture depends on :

  1. boiling point

  2. solubility

  3. magnetic nature

  4. all of these

Correct Option: D

Separation of mixture basically depends on the physical and chemical properties of the components. These factors are state, melting and boiling point, solubility, magnetic nature etc.

A mixture refers to the physical combination of two or more substances on which the chemical identities are retained and are mixed in the form of solutions, suspensions, and colloids.

  1. True

  2. False

Correct Option: A

Soil is a homogeneous mixture.

Write true or flase.

  1. True

  2. False

Correct Option: B

Soil is a heterogeneous mixture.

 So,option-B is correct.