Tag: p- block elements-ii

Questions Related to p- block elements-ii

Which element is not considered as chalcogen?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Selenium

  2. Oxygen

  3. Sulphur

  4. Polonium

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Correct Option: D
Explanation:

In group $16$, the oxygen, sulphur, selenium are called chalcogens (ore-forming) while polonium being radioactive forms a less number of compounds and is not considered as chalcogens.

The properties like ionization potential, electronegativity, electron affinity and power of the catenation of the member in a group depend on many factors. For example, the smaller the size of the atom greater will be the ionization potential. At the same time symmetry in the electronic configuration of the elements also play a part in their ionization energy. Smaller the atomic size, greater will be the mutual electronic repulsion and lesser will be electron affinity. Similarly, the catenation which is a direct result of M - M bond strength is also affected by similar considerations.

The correct decreasing order of catenation among group $16$ elements is _________.

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. $O > S > Se > Te$

  2. $S > O > Se > Te$

  3. $S > Se > Te > O$

  4. $S > Se > O > Te$

Show answer
Correct Option: D
Explanation:

Power of self-catenation generally depends on bond strength (of M - M bond), so the decreasing order of catenation is :


                                  $S$               >                      $Se$           >          $ O$            >                $ Te$
Bond energy               226                                  172                       142                       126
($ kJ mol^{-1}$) 

The bond energy values generally decrease down the group But because of the very small size and consequent mutual inter electronic repulsion oxygen has lower bond energy than $S$ and $Se.$ Due to the large size, $Te - Te$ bond is the weakest.

Therefore, the correct decreasing order of catenation is- 

Which of the following gas is heavier than air?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. $N _2$

  2. $O _2$

  3. $CO _2$

  4. $H _2$

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Correct Option: B,C
Explanation:

The molecular weights of the $N _2,O _2,CO _2,H _2$ are 28,32,44,2 respectively

So $CO _2$ is heavier than air ($O _2$)
Hence option $C$ is correct.

Which of the following elements behaves as a typical non metal?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. S

  2. Se

  3. Te

  4. Po

Show answer
Correct Option: A
Explanation:

In VI A group elements metallic properties increases down the group 
$\therefore $ O,S behave as typical non-metal.

Which of the following does not have oxygen?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Glass

  2. Limestone

  3. Carbohydrates

  4. Ammonia

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Correct Option: D
Explanation:

Glass is made up of silicates, limestone is calcium carbonate. Ammonia does not contain oxygen. 

Nearly half the mass of earth's crust is ________ .

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. oxygen

  2. nitrogen

  3. hydrogen

  4. none of the above

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Correct Option: A
Explanation:

Nearly half the mass of earth's crust is oxygen in the form of silicates, limestone, metallic nitrates. 

Occurrence of oxygen is in:

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. silicates

  2. pencil lead

  3. ammonia

  4. carbohydrates

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Correct Option: A,D
Explanation:

Oxygen occurs in silicates and carbohydrates. 

________ bacteria are microbes that work in the absence of oxygen.

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Anaerobic

  2. Aerobic

  3. Gram-positive 

  4. Gram-negative

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Correct Option: A
Explanation:
Anaerobic bacteria works in the absence of oxygen. 
Example is yeast.

What is the symbol for the element oxygen?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. $Os$

  2. $O$

  3. $Ox$

  4. $Ge$

  5. $N$

Show answer
Correct Option: B
Explanation:
$O$ is the symbol for oxygen. It is having the atomic number 8. It is a highly reactive non  metal. It has oxidising nature.

Which one of the following elements is not detected by Lassaigne's test?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Sulphur

  2. Nitrogen

  3. Oxygen

  4. Chlorine

Show answer
Correct Option: C
Explanation:

It is a general test for the detection of halogens, nitrogen and sulphur in an organic compound. These elements are covalently bonded to the organic compounds. In order to detect them, these have to be converted into their ionic forms. This is done by fusing the organic compound with sodium metal.