Tag: chemistry of non-metals

Questions Related to chemistry of non-metals

Which choice or choices demonstrate amphoterism?
i. $HCl + H _{2}O \rightarrow H _{3}O^{+} + Cl^{-}$ and $H _{2}O + N _{3} \rightarrow OH^{-} + NH _{4}^{-}$
ii. $HS^{-} + HCl \rightarrow Cl^{-} + H _{2}S$ and $HS^{-} + NH _{3} \rightarrow NH _{4}^{+} + S^{2-}$
iii. $HCl + NaOH \rightarrow NaCl + H _{2}O$ and $NaCl + H _{2}O \rightarrow HCl + NaOH$

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. i only

  2. ii only

  3. iii only

  4. i and ii only

  5. i and iii only

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Correct Option: D
Explanation:

Amphoteric compound or ion is a molecule that cn act as both acid as well as base.

In the first reaction, $H _2O$ acts as both acid and base.It accepts proton and loses proton. Hence. it shows amphoterism.
In the second reaction, ${ HS }^{ - }$ does the same thing.
It accepts and loses proton. 
Hence, both shows amphoterism.

Which one among the following can be classified as amphoteric?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $Na _3PO _4$

  2. HCl

  3. NaOH

  4. $HSO^- _4$

  5. $C _2O^{2-} _4$

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Correct Option: D
Explanation:

$\displaystyle HSO^- _4$ can be classified as amphoteric. It can donate a proton and act as an acid. At the same time, it can accept a proton and act as a base.
$\displaystyle HSO^- _4 \rightarrow H^+ + SO _4^{2-}$
$\displaystyle HSO^- _4 + H^+ \rightarrow H _2SO _4$

Amphoteric species is:
chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $Na _3PO _4$

  2. $HSO _4^-$

  3. $KOH$

  4. $HNO _3$

  5. $C _2O^{2-} _4$

Show answer
Correct Option: B
Explanation:

Amphoteric specie is $\displaystyle HSO _4^-$.
It reacts with acid as well as base.
$\displaystyle HSO _4^- + H^+ \rightarrow H _2SO _4$
$\displaystyle HSO _4^-+ OH^- \rightarrow SO _4^{2-} + H _2O$

Which of the following is not a neutral oxide?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $CO$

  2. $N _2O$

  3. $H _2O$

  4. $SO _2$

Show answer
Correct Option: D
Explanation:

Sodium sulphite is formed by passing sulphur dioxide gas through the solution of sodium hydroxide because sulphur dioxide is an acidic oxide.

Which of the following is a neutral oxide?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $NO$

  2. $NO _2$

  3. $N _2O _3$

  4. $N _2O _5$

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Correct Option: A

Which one of the following is an amphoteric oxide?



chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $MnO _{2}$

  2. $ZnO$

  3. $CaO$

  4. $CO _{2}$

Show answer
Correct Option: B
Explanation:

ZnO is amphoteric because it can act with acid as well as base.
$ZnO + NaOH \rightarrow Na _2ZnO _2$
$ZnO+HCl \rightarrow ZnCl _2$

Which one of these is basic?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $ CO _2 $

  2. $ SnO _2$

  3. $ NO _2 $

  4. $ SO _2 $

Show answer
Correct Option: B
Explanation:
All others are nonmetals oxide they are all acidic oxides.

And Sn is an amphoteric both basic and acidic oxide.

Option B is correct.

(1) $N _2 + 2O _2 \leftrightarrow 2NO _2; K _e = 2 \times 10^{-31}$
(2)  $2NO ^+  \leftrightarrow N _2 + O _2;K _e = 2.2 \times 10^{-31}$
(3)  $2N _2O _5 \leftrightarrow 2N _2 + 5O _2 ; K _e = 3.8 \times 10^{-32}$
(4)  $2N _2 + O _2 \leftrightarrow 2N _2O ; K _e = 4 \times 10^{-32}$
From the above data, the most stable oxide is:

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $NO _2$

  2. $NO$

  3. $N _2O _5$

  4. $N _2O$

Show answer
Correct Option: C
Explanation:

Most stable oxide is that whose  formation const, $K _f$ is largest 

$(1)\ N _2 + 2O _2 \leftrightarrow 2NO _2 $   $K _e = 2 \times 10^{-31}$
                                          $K _f = \sqrt{K _e}$  {$\because$ one mole $NO _2$ must be formed}
                                                $= \sqrt{0.2} \times 10^{-15}$
                                                $\approx 0.44 \times 10^{-15}$
$(2)\ 2NO^+ \leftrightarrow N _2 + O _2 $   $K _e = 2.2 \times 10^{-31}$
                                          $K _f = \dfrac{1}{\sqrt{K _e}} = \dfrac{10^{15}}{\sqrt{0.22}}$
                                                 $\approx 0.13 \times 10^{15}$
$(3)\ 2N _2 O _5 \leftrightarrow 2N _2 + 5O _2$     $K _e = 3.8 \times 10^{-32}$
                                                $K _f = \dfrac{1}{\sqrt{K _e}} \approx 0.512 \times 10^{16}$
$(4)\ 2N _2 + O _2 \leftrightarrow 2N _2O $   $K _e = 4 \times 10^{-32}$
                                          $K _f = \sqrt{K _e} = 2 \times 10^{-16}$
$\therefore N _2O _5$ is most stable.

Which of the following oxides is amphoteric in character?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $CaO$

  2. $CO _2$

  3. $SiO _2$

  4. $SnO _2$

Show answer
Correct Option: D
Explanation:

$SnO _2$ shows both acidic and basic properties $\therefore$ it is amphoteric in nature.

Which of the following metals produces acidic oxide ?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $Fe$

  2. $Cu$

  3. $Mn$

  4. $N$

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Correct Option: C
Explanation:

Mn forms acidic oxide $MN _2O _7$ and it is a transtition metal.

$MN _2O _7+H _2O\longrightarrow 2HMNO _4$