Tag: p-block elements

Questions Related to p-block elements

When three parts of conc. HCl and one part of conc. $HNO _{3}$ is mixed, a compound 'X' is formed. The correct option related to 'X' is:

  1. 'X' is known as aqua-regia

  2. 'X' is used for dissolving gold

  3. 'X' is used for decomposition of salts of weaker acids

  4. both (a) and (b)


Correct Option: D
Explanation:

Aqua regia is also called as royal water is a mixture of nitric acid and hydrochloric acid in the  molar ratio of 1:3. Aqua regia is a yellow-orange fuming liquid.Aqua regia is used for the decomposition of weak acids.

Hene option D is correct.

A and B are two gases. A is identified with the glass rod dipped in $NH _3$ and $\mathrm{B}$ is identified with the glass rod dipped in $HCl$. Then A and B are :

  1. $\mathrm{H}\mathrm{Cl},\ \mathrm{N}\mathrm{O} _{2}$

  2. $\mathrm{H}\mathrm{Cl},\ \mathrm{N}\mathrm{H} _{3}$

  3. $\mathrm{N}\mathrm{H} _{3}$, H$\mathrm{Cl}$

  4. $\mathrm{N}\mathrm{H} _{3},\ \mathrm{S}\mathrm{O} _{2}$


Correct Option: B
Explanation:

When glass rod dipped in $NH _3$, it is $HCl$ which reacts to form $NH _4Cl$ and when dipped in $HCl$, it is $NH _3$ which react to form $NH _4Cl$. 

When vanilla extract added to _______  it still retains the sweet pleasant smell.

  1. dil . HCl

  2. conc. HCl

  3. dil. NaOH

  4. conc. NaOH


Correct Option: A
Explanation:

When vanilla extract is added to dil. HCl, it still retains the sweet pleasant smell. Its smell changes when added to a base.

Statement I: $HCl$ is considered to be an acid.

Statement II: $HCl$ is a proton donor.

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is correct.

  5. Both the Statement 1 and Statement 2 are not correct.


Correct Option: A
Explanation:

An acid is a substance that can donate a hydrogen ion ($H^+$) or proton to another substance. $HCl$ can donate proton so it is a acid.

The reaction of zinc metal and $HCl$ produces which of the following?
i. $H _2(g)$
ii. $Cl _2(g)$
iii. $ZnCl _2(aq)$

  1. ii only

  2. iii only

  3. i and ii only

  4. i and iii only

  5. i, ii and iii


Correct Option: D
Explanation:

Zn being an active metal it readily reacts HCl at room temperature.

$Zn+HCl\rightarrow ZnCl _{ 2 }+{ H } _{ 2 }$
It is a diplacement reation. 
Zinc displaces hydrogen from $HCl$.

Which of the following acids is capable of dissolving gold?

  1. Hydrochloric acid

  2. Nitric acid

  3. Sulfuric acid

  4. A combination of A and B

  5. A combination of A and C


Correct Option: D
Explanation:

Aqua regia is a mixture of hydrochloric acid and nitric acid in the ration $3:1$. It is a very strong acid and can dissolve any metals including noble metals like gold and silver.

Which of the following scientist gave the name hydrochloric acid to $HCl$?

  1. Joseph Louis Gay-Lussac 

  2. Lavoiser

  3. Cavendish

  4. Glauber


Correct Option: A
Explanation:

Hydrochloric acid was earlier called muriatic acid. Gay-Lussac coined the name hydrochloric acid in the year 1814.

$HCl$ gas can fume in moist air.

  1. True

  2. False


Correct Option: A
Explanation:

Concentrated hydrochloric acid or fuming HCl acid forms acidic mists. Both the mist and the solution have a corrosive effect on human tissue like eyes, skin, intestines etc. This moisture can be prevented during the preparation of HCl by using a guard tube with calcium chloride in it.

Chlorine gas removes hydrogen from $H _2S$ solution, forming HCl and leaving behind sulphur.

  1. True

  2. False


Correct Option: A
Explanation:

Chlorine gas reacts with hydrogen sulphide forming $HCl$ and sulphur.
$2Cl _2+2H _2S\rightarrow 4HCl+S _2$

There are two colourless solutions (A) and (B), both give white ppt with $AgNO _3$ which dissolves in $aq \, NH _3$. Also (A) on reaction with $H _2O$ gives orange turbidity while (B) gives white turbidity. Identify (A) and (B). 

  1. (A) $SbCI _3 ;\, \, \,$ (B) $BiCI _3$

  2. (A) $BiCI _3 ;\, \, \,$ (B) $SbCI _3$

  3. (A) $SeCI _3;   \, \, \,$ (B) $BiCI _3$

  4. (A) $BiCI _3;   \, \, \,$ (B) $SeCI _3$


Correct Option: A
Explanation:

$SbCI _3$ or $BiCI _3 + AgNO _3 \longrightarrow \underset {white\, \, ppt }{ AgCI\downarrow}$ (due to $CI^-$)

              $AgCI + 2NH _3 (aq) \longrightarrow [\underset{soluble}{Ag(NH _3) _2}] CI$

                      $SbCI _3 + H _2O \longrightarrow \underset{orange}{SbOCI}\downarrow + 2HCI$

                  $SbOCl + 2HCI \longrightarrow \underset{soluble}{SbCI _3}+H _2O$

                      $BiCI _3 + H _2O \longrightarrow \underset{white}{BiOCI\downarrow}+ 2HCI$

                  $BiOCI + 2HCI \longrightarrow \underset{soluble}{BiCI _3}+H _2O$
Turbidity can be dissolved in dil. $HCl$.