Tag: chemistry

Questions Related to chemistry

Who determined the mass of a neutron?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. John Dalton (early 1800's)

  2. Ernest Rutherford (1911)

  3. Niels Bohr (1913)

  4. James Chadwick (1932)

Show answer
Correct Option: D
Explanation:

The presence of neutron and its mass was determined by James Chadwick. Neutron was discovered by bombarding $\alpha-$particles on $Be$. On doing so, highly energetic beam of radiation was observed by Chadwick. Thus mass of neutron was determined by James Chadwick.

Whose experiment proved the existence of the nucleus?

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. John Dalton (early 1800's)

  2. Ernest Rutherford (1911)

  3. Niels Bohr (1913)

  4. James Chadwick (1932)

Show answer
Correct Option: B
Explanation:

The $\alpha-$ ray scattering-gold foil experiment by Ernest Rutherford gave substantial evidence for  existence of nucleus in $1911$. Thus the existence of nucleus was proved by Rutherford's experiment.

Neutron was discovered by:

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. J.J. Thomson

  2. Chadwick

  3. Rutherford

  4. Priestley

Show answer
Correct Option: B
Explanation:

 Neutron was discovered by Chadwick.
To overcome the failure of proton electron hypothesis, Rutherford, in 1920, proposed the existence of neutral particle made from close combination of proton and electron. He named it neutron.
In 1932, Lord Chadwick proved the existence of neutron by bombarding lighter elements (boron and beryllium) with alpha particles which resulted in the emission of highly penetrating neutral radiation.

The neutron is a neutral (non-electrical) particle in the centre of the atom. It was discovered when a tiny piece of the metal, beryllium, was bombarded with alpha particles. This discovery was made by:

chemistry what is inside atom discovery of neutrons structure of atoms discovery of subatomic particles

  1. Chadwick

  2. Rutherford

  3. Niels Bohr

  4. Enrico Fermi

Show answer
Correct Option: A
Explanation:
In 1930, it was discovered that Beryllium, when bombarded by alpha particles, emitted a very energetic stream of neutral radiation. In 1932, Chadwick proposed that neutral radiation consists of a new type of neutral particles - neutrons.

A translucent white waxy solid (A) reacts with excess of chlorine to give a yellowish white powder (B). (B) reacts with organic compounds containing -OH group converting them into chloro derivatives. (B) on hydrolysis gives (C) and is finally converted to phosphoric acid. (A), (B) and (C) are?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $P _{4}$,$PCl _{3}$,$H _{3}PO _{4}$

  2. $P _{4}$,$PCl _{5}$,$H _{3}PO _{3}$

  3. $P _{4}$,$PCl _{5}$,$POCl _{3}$

  4. $P _{4}$,$PCl _{3}$,$POCl _{3}$

Show answer
Correct Option: C
Explanation:

A translucent white waxy solid (A) reacts with excess of chlorine to give a yellowish white powder (B). Here B is $PCl _5$.$PCl _5$ reacts with organic compounds containing -OH group converting them into chloro derivative $POCl _3. $.$PCl _5$ on hydrolysis gives (C).C is $POCl _3$ and is finally $POCl _3$ converted to phosphoric acid.

So  (A), (B) and (C) are $P _{4}$,$PCl _{5}$,$POCl _{3}$.

Hence option C is correct.

$\mathrm{P}\mathrm{Cl} _{3}$ is prepared by the action of $\mathrm{Cl} _{2}$ on :

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. $ \mathrm{P} _{2}\mathrm{O} _{3}$

  2. $ \mathrm{P} _{2}\mathrm{O} _{5}$

  3. White $\mathrm{P}$

  4. $\mathrm{H} _{3}\mathrm{P}\mathrm{O} _{3}$

Show answer
Correct Option: C
Explanation:

White P is reactive due to strain.
$P _{4}+6Cl _{2}\ \to \ 4PCl _{3}$
(White P)

Which of the following exist as dimer :

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. NO

  2. $NO _{2}$

  3. $P _{2}O _{3}$

  4. All

Show answer
Correct Option: D
Explanation:

All have dimer forms

$NO$ as $N _{2}O _{2}$

$NO _{2}$ as $N _{2}O _{4}$

$P _{2}O _{3}$ as $P _{4}O _{6}$

What is the oxidation state of Phosphorus in ${P}{Cl} _{3}$?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${+}{5}$

  2. ${+}{3}$

  3. ${+}{1}$

  4. ${-}{3}$

Show answer
Correct Option: B
Explanation:

The oxidation state of ${P}$ in ${P}{Cl} _{3}$ is ${+3}$.
Each Chlorine atom has an oxidation number of ${-1}$. There are three chlorine atoms, hence the total oxidation number of the Chloride ions in ${-3}$. ${PCl} _{3}$ molecule is neutral. Hence the oxidation number of Phosphorus should be ${+3}$

What is the boiling point of ${PCl} _{3}$?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${-93.6}^{o}$ ${C}$

  2. ${169}^{o}$ ${C}$

  3. ${100}^{o}$ ${C}$

  4. ${76.1}^{o}$ ${C}$

Show answer
Correct Option: D
Explanation:

The boiling point of ${PCl} _{3}$ is ${76.1}^{o}$ ${C}$

What is the hybridization of Phosphorus Trichloride?

chemistry p- block elements-ii compounds of phosphorus - pcl3 phosphorus halides compounds of phosphorus compounds of phosphorus- pcl5

  1. ${sp}^{3}$

  2. ${sp}^{2}$

  3. ${sp}$

  4. None of these

Show answer
Correct Option: A
Explanation:

The hybridization of ${PCl} _{3}$ is ${sp}^{3}$. Phosphorus has five electrons in its outermost shell. Thus it forms three sigma bonds with three neighbouring Chlorine atoms. The remaining two electrons remain as a lone pair on Phosphorus atom. Thus these three sigma bonds and one lone pair, make this molecule ${sp}^{3}$ hybridized.