Tag: chemistry

Questions Related to chemistry

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

Statement II: $HCl$ is a proton donor.

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  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.

Show answer
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. $ZnCl _2(aq)$

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. ii only

  2. iii only

  3. i and ii only

  4. i and iii only

  5. i, ii and iii

Show answer
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?

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. Hydrochloric acid

  2. Nitric acid

  3. Sulfuric acid

  4. A combination of A and B

  5. A combination of A and C

Show answer
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 $HCl$?

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. Joseph Louis Gay-Lussac 

  2. Lavoiser

  3. Cavendish

  4. Glauber

Show answer
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.

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. True

  2. False

Show answer
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.

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. True

  2. False

Show answer
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). 

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  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) $SeCI _3$

Show answer
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. $HCl$.

 $\displaystyle { HCl(g) }$ and $\displaystyle { HCl (aq) }$ have different behaviour towards litmus.

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

$HCl$ can produce ions only in aqueous solution making aqueous $HCl$acidic. So, aqueous $HCl$ turns blue litmus red whereas dry $HCl$ does not dissociate and acts inert to litmus.

Aqua-regia dissolves gold. 
which is correct?

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. Aqua regia, or nitro-hydrochloric acid is a highly corrosive mixture of acids , a fuming yellow or red solution.

  2. The mixtures is formed by freshly mixing concentrated nitric acid and hydrochloric acid hoptimally in a volume ratio of 1:3.

  3. it can dissolve the noble metalsgold and platinum

  4. all of these

Show answer
Correct Option: D
Explanation:

Aqua regia, or nitro-hydrochloric acid is a highly corrosive mixture of acids, a fuming yellow or red solution. The mixtures is formed by freshly mixing concentrated nitric acid and hydrochloric acid hoptimally in a volume ratio of 1:3. It was named so because it can dissolve the noble metalsgold and platinum
Hence answer 1 is correct.

What is the pH number of hydrochloric acid?

chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

  1. Below 7

  2. Above 7

  3. 7

  4. Between 8 and 10

Show answer
Correct Option: A
Explanation:

The pH of acids is given by the pH scale from 1-7. Strength of acids increases by moving down the scale from 7 to 1. High acidity ranks as 1 on the pH scale and 7 are neutral. HCl is highly acidic so it has pH less than 7 while on this scale basicity increases going from 7 to 14. So all the acids have pH under 7.


Option A is correct.