Tag: allotropy of carbon

Questions Related to allotropy of carbon

 $NaHCO _3$ is used as fire extinguisher.

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. True

  2. False

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Correct Option: A
Explanation:

Fire extinguisher contains sodium bicarbonate in water and sulphuric acid in a separate container inside it. When the fire extinguisher is released by pressing the knob on it, the sulphuric acid mixed with sodium bicarbonate solution producing a lot of carbon dioxide gas.

$2NaHCO _3 + H _2SO _4\rightarrow Na _2SO _4 + 2H _2O + 2CO _2$ 

Carbon dioxide gas is neither combustible nor helps in combustion. It is heavier than air and offs the supply of oxygen from air and hence removes the fire. So, sodium bicarbonate is used in fire extinguishers. So the given statement is true.

Hence option A is correct.

Which of the following is used as fire extinguisher ?

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. Sodium carbonate

  2. Sodium bicarbonate

  3. Sodium chloride

  4. Ammonium chloride

Show answer
Correct Option: B
Explanation:

Sodium bicarbonate, also called sodium hydrogen carbonate, or bicarbonate of soda,$NaHCO _3$, is a source of carbon dioxide and so is used as an ingredient in baking powders, in effervescent salts and beverages, and as the main constituent of dry-chemical fire extinguishers.

With reference to sodium bicarbonate which statement is true from the options.

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. Statement 1: Sodium bicarbonate ($NaHCO _3$)

  2. Statement 2: It reduces stomach acid  

  3. Statement 3: It is used to relieve heartburn, sour stomach, or acid  

  4. All are true 

Show answer
Correct Option: D
Explanation:

These are the right properties of Sodium Bicarbonate

Sodium bicarbonate ($NaHCO _3$)
It reduces stomach acid 

It is used to relieve heartburn, sour stomach, or acid   

Soda acid for extinguisher contains:

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. sodium carbonate and nitric acid

  2. sodium hydrogen carbonate and sulphuric acid

  3. sodium carbonate and carbonic acid

  4. sodium chloride and sulphuric acid

Show answer
Correct Option: B
Explanation:

Soda acid for extinguisher contains sodium hydrogen carbonate and sulphuric acid. The reaction between sodium bicarbonate solution and sulfuric acid expels pressurized water onto a fire.
$2NaHCO _3+H _2SO _4 \rightarrow Na _2SO _4+2H _2O+2CO _2$

 Select the correct choice:

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $KHCO _3$ is less soluble in water than $NaHCO _3$.

  2. $CaC _2O _4$ is soluble in water and alkalies.

  3. $Ca(HCO _3) _2$ an obtained in solid state.

  4. $BeF _2$ is water soluble but $CaF _2$ is water insoluble.

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Correct Option: A
Explanation:
using Fazan's rule we can say that $KHCO _3$ is less soluble in water than $NaHCO _3$

Calcium oxalate is an ionic compound with the chemical formula $CaC _2O _4$ and a salt of oxalic acid. It's highly insoluble and dissolves poorly in water. One method for dissolving calcium oxalate in the lab is the application of a compound called ethylenediaminetetraacetic acid or EDTA. EDTA is highly effective at binding the calcium ions and thereby decreasing the concentration of calcium in solution, shifting the reaction equilibrium so that more calcium oxalate will dissolve.

$NaHCO _3$ is stable to heat and normal temperature hence isolated as a solid.

However, $Ca(HCO _3) _2$ is not stable at these temperatures and hence is isolated from water, also bicarbonates of alkaline earth metals are reactive with atmospheric $CO _2$ leading to formation of  $CaCO _3$.


Hydration energy decreases down the group ,so solubility decreases down the group


Which salt can furnish $H^{+}$ in its aqueous solution?

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $NaH _{2}PO _{2}$

  2. $Na _{2}HPO _{3}$

  3. $Na _{2}HPO _{4}$

  4. all of these

Show answer
Correct Option: B
Explanation:

  • Disodium hydrogenphosphite$ ( Na _2HPO _3)$ is a salt of phosphorus acid $( H _3PO _3)$, which is a dibasic acid. A dibasic acid has only two acidic or replaceable hydrogen atoms in its molecule. In $( H _3PO _3)$, the third hydrogen is directly bonded to phosphorus and so it is non-acidic.
  • $  Na _2HPO _3$ is formed when the two acidic hydrogens are replaced by sodium. In other words, this salt is the product of complete neutralisation of phosphoric acid by sodium hydroxide. It does not have any acidic hydrogen. So, it can furnish any $H^+$ in its aqueous solution.

Sodium bicarbonate can react with:

chemistry allotropy of carbon preparation, properties and uses of baking soda chemical from common salt compounds of carbon

  1. $Na _{2}CO _{3}$

  2. $NaOH$

  3. $NaH$

  4. $HCl$

Show answer
Correct Option: D
Explanation:

Sodium bicarbonate mixed with water can be used as an antacid to treat acid indigestion and heartburn. Its reaction with stomach acid produces salt, water, and carbon dioxide: 

${ NaHCO } _{ 3 }$ + $HCl$ $\rightarrow$ $NaCl$ + ${ H } _{ 2 }O$ + ${ CO } _{ 2 }$(g)

Fullerene, an allotrope of carbon, has 60 carbon atoms joined together and no other element in it. There are various types of fullerenes. $C _{60}, C _{70}, C _{74}$ and $C _{78}$ are the members of the fullerene family. Identify the property due to which such large numbers of carbon atoms are joined together in this molecule :

chemistry allotropy of carbon organic compounds allotropes of carbon versatile nature of carbon

  1. Isomerism

  2. Homologous

  3. Catenation

  4. Metamerism

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Correct Option: C
Explanation:

Catenation is a self-linking property which is maximum present in carbon, because of this property large number of carbon atoms joined together to form molecule.