Tag: chemistry

Questions Related to chemistry

The order (lowest to highest) of e/m (charge/mass) ratio for electron (e), proton (p), neutron (n) and alpha particle $(\alpha)$ is:

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. $e, p, n, \alpha$

  2. $n, p, e, \alpha$

  3. $n, p, \alpha, e$

  4. $n, \alpha, p, e$

Show answer
Correct Option: D
Explanation:
The increasing order (lowest to highest) of e/m (charge/mass) ratio is $ n < \alpha < p < e$.Neutron being neutral has zero charge and lowest e/m ratio. An electron has a unit charge but negligible mass. Hence, the electron has maximum e/m ratio.For an alpha particle, the e/m ratio is 2/4 or 0.5.For proton, e/m ratio is 1/1 or 1.


Which of the following doesn't have charge?

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. Proton

  2. Neutron

  3. Electron

  4. Isotope

  5. Ion

Show answer
Correct Option: B
Explanation:

Neutron has zero unit charge.
The neutron is a subatomic particle, symbol n or $n^0$, with no net electric charge and a mass slightly larger than that of a proton. Protons and neutrons, each with mass approximately one atomic mass unit, constitute the nucleus of an atom, and they are collectively referred to as nucleons

Neutron does not get deflected in the presence of electric field.

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Neutrons are neutral particles. Thus, they are not affected by the electric field.

Hence, they does not get deflected in the presence of electric field.

 Which of the following would not be attracted or deflected while traveling through an electric field?
I. Gamma ray
II. Beta particle
III. neutron.

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. i only

  2. ii only

  3. i and ii Only

  4. i and iii only

Show answer
Correct Option: D
Explanation:

Gamma rays and neutrons have no charge as they are neutral, hence, these would not be attracted or deflected while traveling through an electric field.

Doubly magic nucleus is:

chemistry structure of the atom neutrons discovery of neutrons structure of atoms

  1. $ _{ 82 }^{ 207 }{ Pb }$

  2. $ _{ 82 }^{ 206 }{ Pb }$

  3. $ _{ 82 }^{ 208 }{ Pb }$

  4. $ _{ 83 }^{ 209 }{ Bi }$

Show answer
Correct Option: C
Explanation:

Doubly magic nucleus is $\displaystyle _{ 82 }^{ 208 }{ Pb }$. It has 82 protons and $\displaystyle 208-82=126$ neutrons. 82 and 126 are magic numbers.

A mixture of powdered salt and sugar can be separated by the process of winnowing.

chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

No, we cannot separate powdered salt and sugar by winnowing beacuse they are forming homogeneous solution.


The constituents of a heterogeneous mixture are X, Y and Z. 
If mixture of X and Y taken separately then, X can be separated using magnetic separation from Y. If mixture Y and Z is taken then it can be separated using distillation method.

Which of the following mixture can be X, Y, Z?
chemistry pure substances and mixtures: separation of mixtures dry methods of separation process of separating components of a mixture method of separation

  1. Iron, salt, water.

  2. Sulphur, carbon disulphide, water.

  3. Gun powder, common salt, water.

  4. Iodine, sand, alcohol.

Show answer
Correct Option: A

Which technique can be used to separate iron from mixture of iron and copper?

chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

  1. Sublimation

  2. Magnetic separation

  3. Solvent extraction

  4. Sedimentation

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Correct Option: B
Explanation:

As iron can be attracted by magnets, so magnetic separation method method can be used to separate iron from the mixture.

State a method to separate ammonium chloride from a mixture of ammonium chloride and potassium chloride.

chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

  1. Sedimentation

  2. Sublimation

  3. Magnetic separation

  4. Solvent extraction

Show answer
Correct Option: B
Explanation:

Ammonium chloride sublimes on heating therefore it is easy to remove it by sublimation from a mixture of ammonium chloride and potassium chloride.

Which method can be used to separate two solid mixtures one of which dissolves in a particular solvent and other does not?

chemistry mix and separate dry methods of separation process of separating components of a mixture method of separation

  1. Separating funnel

  2. Sublimation

  3. Magnetic separation

  4. Solvent extraction

Show answer
Correct Option: D
Explanation:

The two solid mixtures, one of which dissolves in a particular solvent and other does not, can be separated by solvent extraction method.