Tag: chemistry

Questions Related to chemistry

Which of the following are not the characteristic property of non-metal?

  1. Sonorous

  2. Not malleable

  3. Not ductile

  4. Not lustrous


Correct Option: A
Explanation:

Non-metals are not sonorous as they do not produce sound when they are beaten. 


 Hence, option A is correct.

Non-metal oxides when react with water forms:

  1. bases

  2. acids

  3. neutral compounds

  4. none of the above


Correct Option: B
Explanation:

Metal oxides forms bases and non metal oxides forms acids when they react with water. Metal oxides when they reacted with water it produces bases. Hence, option A is correct.

Which of the following are characteristic property of non metals?

  1. Not malleable

  2. ductile

  3. Malleable

  4. Sonorous


Correct Option: A
Explanation:

Non metals are generally not malleable as they can not be beaten into thin sheets. Substance which can be beaten into thin sheets are called malleable. Hence, option A is correct.

Bromine is

  1. Liquid metal

  2. Liquid non metal

  3. Gaseous non metal

  4. Solid non metal


Correct Option: B
Explanation:

Non metals are generally solids and gases.They do not exist  as liquids except Bromine.Bromine is liquid.
Hence option B is correct.

Boron can undergo the following reactions with the given enthaly changes:
Assume no other reactions are occurring. If in a container (operating at constant pressure) which is isolated from the surrounding, mixture of are passed over excess of B(s), then calculate the molar ratio so that temperature of the container do not change :
${\text{2B}}\left( {\text{s}} \right){\text{ + }}\dfrac{{\text{3}}}{{\text{2}}}{{\text{O}} _{\text{2}}}\left( {\text{g}} \right) \to {{\text{B}} _{\text{2}}}{{\text{O}} _{\text{3}}}\left( {\text{s}} \right);\;\Delta H =  - 1260\;KJ$
${\text{2B}}\left( {\text{s}} \right){\text{ + 3}}{{\text{H}} _{\text{2}}}\left( {\text{g}} \right) \to {{\text{B}} _2}{H _6}\left( g \right);\;\Delta H = 30KJ$

  1. 15 : 3

  2. 42 : 1

  3. 1 : 42

  4. 1 : 84


Correct Option: C

Moissan boron is:

  1. 95 - 98% pure amorphous boron

  2. 75 - 78% pure amorphous boron

  3. 95-98% pure crystalline boron

  4. 75 - 78% pure crystalline boron


Correct Option: A
Explanation:

Moissan Boron is amorphous Boron of ultra high purity.

For healthy growth of plants, boron is an essential:

  1. minor nutrient

  2. major nutrient

  3. both

  4. major metal


Correct Option: A
Explanation:

Boron is essential for the growth of higher plants. The primary function of the element is to provide structural integrity to the cell wall in plants. 


Other functions likely include the maintenance of the plasma membrane and other metabolic pathways.

So it is essential micronutrient for plants.

Option A is correct.

Which of the following is used as control rods in nuclear reactors?

  1. Al

  2. Ga

  3. Tl

  4. B


Correct Option: D
Explanation:

Boron carbide is used as a control rod material.

Diborane undergoes cleavage and gives aduct with
(i) CO
(ii) $ H _2O $
(iii) $ N(Me) _3 $
(iv) $ NH _3 $

  1. i, ii

  2. i, iii

  3. ii, iii

  4. i, iv


Correct Option: A

Borazole is an isoster of

  1. Benzene

  2. Propane

  3. Naphthalene

  4. Phenol


Correct Option: A
Explanation:

Both have number of electrons and similar structure and properties.
Isosteres are molecules or ions of similar size containing the same number of atoms and valence electrons, e.g., O^2-, F-, Ne.