Tag: p-block elements

Questions Related to p-block elements

Spirit of salt is the other name of :

  1. hydrochloric acid

  2. sulphuric acid

  3. nitric acid

  4. hydroiodic acid


Correct Option: A
Explanation:

Hydrochloric acid is a clear, colorless, highly pungent solution of hydrogen chlorine in water. It is also known as spirit of salt and muriatic acid.

The metal that cannot displace hydrogen from dilute hydrochlocric acid is 

  1. aluminium

  2. iron

  3. copper

  4. zinc

  5. magnesium


Correct Option: C

Name the ion(s) obtained when $HCl$ dissociates in aqueous solution.

  1. ${ H } _{ 3 }{ O }^{ + }$

  2. ${ Cl }^{ - }$

  3. Both $A$ and $B$

  4. None of these


Correct Option: C
Explanation:

Acidic nature of $HCl$ is due to hydrogen ions which reacts with water to form hydronium ions. 
$HCl(g) +{ H } _{ 2 }O \rightleftharpoons { H } _{ 3 }{ O }^{ + }+{ Cl }^{ - }$

Equations relating to acidic properties of an aq. solution of HCl gas is/are :

  1. $HCl\left( g \right) +{ H } _{ 2 }O\rightleftharpoons { H } _{ 3 }{ O }^{ + }+{ Cl }^{ - }$

  2. $Zn\left( OH \right) _{ 2 }+2{ H }Cl\rightarrow { ZnCl } _{ 2 }+2{ H } _{ 2 }O$

  3. $ { MnO } _{ 2 }+4HCl\rightarrow { MnCl } _{ 2 }+{ Cl } _{ 2 }+2{ H } _{ 2 }O$

  4. all of the above


Correct Option: D
Explanation:

1) $HCl\left( g \right) +{ H } _{ 2 }O\rightleftharpoons { H } _{ 3 }{ O }^{ + }+{ Cl }^{ - }$
2) ${ 2KMnO } _{ 4 }+16HCl\rightarrow { 2MnCl } _{ 2 }+{ 8H } _{ 2 }O+2KCl+{ 5Cl } _{ 2 }$
3) $ { MnO } _{ 2 }+4HCl\rightarrow { MnCl } _{ 2 }+{ Cl } _{ 2 }+2{ H } _{ 2 }O$
4) $Zn\left( OH \right) _{ 2 }+{ H }Cl\rightarrow { ZnCl } _{ 2 }+{ H } _{ 2 }O$

All of the above equation shows the acidic properties of hydrochloric acid.

Which of the following has pungent odour?

  1. $H _2SO _4$

  2. $CH _3COOH$

  3. HCl

  4. Both (a) and (b)


Correct Option: C
Explanation:

Hydrochloric acid has a pungent smell and is a colourless gas.

    Appearance  Reaction with dilute $HCl$  Reaction with dilute $HNO _3$
 Unknown metal #1  Dull gray solid with white oxide coating Dissolved with bubbles of clear gas   Dissolved with bubbles of clear gas
 Unknown metal #2  Solid; lustrous, smooth silver-gray surface  No reaction  Dissolved with bubbles of orange gas

Identify metal #1.

  1. Mercury

  2. Copper

  3. Zinc

  4. Iron

  5. Silver


Correct Option: C
Explanation:

 Zinc being an active metal readily reacts with hydrochloric acid at room temperature to form soluble zinc chloride and hydrogen.

   $Zn+2{ H }Cl\rightarrow Zn{ Cl } _{ 2 }+{ H } _{ 2 }$
Zinc reacts with dilute nitric acid  and libreates nitric oxie.
$3Zn+{ 8HNO } _{ 3 }\rightarrow { 3Zn(NO _{ 3 }) } _{ 2 }+4{ H } _{ 2 }O+2NO$

Statement I : The reactivity of powdered zinc will be greater than the larger piece of zinc of the same mass with $\displaystyle HCl$.
Statement II : The larger piece of zinc of the same mass has more surface area than the powdered zinc.

  1. True, False

  2. False, True

  3. True, True

  4. False, False


Correct Option: A
Explanation:

Statement I : The reactivity of powdered zinc will be greater than the larger piece of zinc of the same mass with HCl.
Statement II : The  powdered zinc has more surface area than the larger piece of zinc of the same mass. Higher is the surface area, higher is the reactivity.

Which of the following is produced by the reaction of zinc metal, $Zn$ and hydrochloric acid, $HCl$?
I. $H _2(g)$
II. $Cl _2(g)$
III. $Zn^{2+}(aq)$

  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:

$\displaystyle H _2$ and $\displaystyle Zn^{2+}$ is produced by the reaction of zinc metal, $Zn$, and hydrochloric acid, $HCl$.
$\displaystyle Zn + 2HCl  \rightarrow ZnCl _2 + H _2$

The addition of dilute $HCl$ to unknown metal produced a transparent gas. What is the likely identity of this gas?

  1. $Cl _{2}$

  2. $H _{2}$

  3. $O _{2}$

  4. $CO _{2}$

  5. $NO _{2}$


Correct Option: B
Explanation:

Metals that come before hydrogen in the reactivity series form their corresponding chlorides when heated with HCl and liberate hydrogen gas.

Eg:
$Ca+2HCl\rightarrow { CaCl } _{ 2 }+{ H } _{ 2 }$


| |  Appearance |  Reaction with dilute $HCl$ |  Reaction with dilute $HNO _3$ | | --- | --- | --- | --- | |  Unknown metal #1 |  Dull gray solid with white oxide coating | Dissolved with bubbles of clear gas  |  Dissolved with bubbles of clear gas | |  Unknown metal #2 |  Solid; lustrous, smooth silver-gray surface |  No reaction |  Dissolved with bubbles of orange gas |

Identify metal #2.

  1. Carbon

  2. Copper

  3. Zinc

  4. Sodium

  5. Silver


Correct Option: E
Explanation:

Silver has a lustrous smooth gray surface.

It reacts with $HNO _3$ as:
$3Ag+2{ HNO } _{ 3 }\rightarrow { 4AgNO } _{ 3 }+{ NO } _{ 2 }+{ H } _{ 2 }O$.
The orange gas obtained is $NO _2$.