Tag: p- block elements-ii

Questions Related to p- block elements-ii

Only one element of _______form hydride.

  1. group 6

  2. group 7

  3. group 8

  4. group 9


Correct Option: A
Explanation:

Only one element of chromium from group $6$,that is $CrH$.

So,the answer is only one element of group $6$ forms hydrites.
These type of hybrides are classified into metalic or non-stoichiometric type of hydrides.

The smog is essentially caused by the presence of 

  1. $ \mathrm { O } _ { 2 } \text { and } \mathrm { O } _ { 3 } $

  2. $ O _ { 3 } \text { and } N _ { 2 } $

  3. Oxides of sulphur and nitrogen

  4. $ O _ { 2 } \text { and } N _ { 2 } $


Correct Option: C
Explanation:

The atmospheric pollutants or gases that form smog are released in the air when fuels are burnt. When sunlight and its heat react with these gases and fine particles in the atmosphere, smog is formed. It is purely caused by air pollution. Ground level ozone and fine particles are released in the air due to complex photochemical reactions between volatile organic compounds (VOC), sulfur dioxide (SO2) and nitrogen oxides (NOx).

These VOC, SO2, and NOx are called precursors. The main sources of these precursors are pollutants released directly into the air by gasoline and diesel-run vehicles, industrial plants and activities, and heating due to human activities

In which one of the following reactions, a 16 group element will get precipitated ?

  1. $ Na _2S _2O _3 + CI _2+H _2O \longrightarrow $

  2. $ Na _2SO _3 - CI _2+H _2O \longrightarrow $

  3. $ SO _2+2H _2O+CI _2 \longrightarrow $

  4. $ 2FeSO _4+H _2SO _4+CI _2 \longrightarrow $


Correct Option: A

The one with lowest electron affinity in group 16 is 

  1. Oxygen

  2. Sulphur

  3. Selenium

  4. Tellurium


Correct Option: A

Which of the following bonds has the least energy?

  1. $Se-Se$

  2. $Te-Te$

  3. $S-S$

  4. $O-O$


Correct Option: B
Explanation:

As we move down the group, size increases and because of that M-M bond become weaker and Te-Te have least bond energy.

Among $CH _4, NH _3$ and $H _2O$, acidity of $H _2O$ is maximum because :

  1. Oxygen contains two lone pairs of electrons.

  2. Bond angle on $H _2O$ is less than $109^{\small\circ}28'$ due to $VSEPR$.

  3. Oxygen is more electronegative than $C$ or $N$.

  4. $H _2O$ is an associated liquid.


Correct Option: C
Explanation:

As oxygen is more electronegative so conjugate base in case of $H _2O$ is more stable and it is more basic than others.


The electronegativity increases along the period. Acidity of hydrides of corresponding elements also increase with increase in electronegativity of these elements. 

Identify the group 16 $(VI\space A)$ elements which is the most electronegative ?

  1. $ O $

  2. $ S $

  3. $ Te$

  4. $ Po $


Correct Option: A
Explanation:

All theses O,S,Se,Te,Po are group 16 elements from top to bottom.As we move from top to bottom in a group as the size increses the electronegativity  decreases.So most electronegative element is Oxygen
The order of electronegativity is O>S >Se>Te.Po.
Hence option A is correct.

State true or false.

Sulphur is an insulator while selenium and tellurium are semiconductors.
  1. True

  2. False


Correct Option: A
Explanation:

The trend from nonmetallic to metallic character upon going down the group is exemplified by the conductivities of these elements. Sulphur is an insulator, selenium and tellurium are semiconductors.


In addition, the conductivities of sulphur, selenium, and tellurium increase with increasing temperature, behaviour typical of non-metals.

Name of the group-16 element which shows maximum catenation.

  1. Oxygen

  2. Sulphur

  3. Selenium

  4. Tellurium


Correct Option: B
Explanation:

The greater the element-element bond strength, the higher is the tendency towards catenation. 

As the size increases from S to Te, the bond dissociation energy decreases. O - O bond energy is, however, smaller than that of S-S because of inter electronic repulsions within the smaller size of oxygen atoms. 

Thus, sulphur has a maximum tendency towards catenation.

In 16 group element, sulphur, selenium and tellurium are respectively :

  1. Insulator, Semiconductors and Semiconductor.

  2. Semiconductors , Insulator and Insulator.

  3. Insulator, Insulator and Semiconductor.

  4. Semiconductors, Insulator and Semiconductor.


Correct Option: A
Explanation:
 Sulphur is non metal.It has the properties of poor conductor of both heat and electricity.It is weak,dull and can be easily breakable.

As we  move from top to bottom in  group the conductivity of elements increases so the sulfur, selenium  and tellurium are Insulator, Semiconductors and Semiconductors respectively.

Hence option A is correct.