Tag: chemistry of non-metals

Quizzes (6) Questions (122)

Questions Related to chemistry of non-metals

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

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 $NaCl + H _{2}O \rightarrow HCl + NaOH$

  1. i only

  2. ii only

  3. iii only

  4. i and ii only

  5. i and iii only
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

Which one among the following can be classified as amphoteric?

  1. $Na _3PO _4$

  2. HCl

  3. NaOH
  4. $HSO^- _4$
  5. $C _2O^{2-} _4$
Reveal answer Fill a bubble to check yourself
D Correct answer
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.
$\displaystyle HSO^- _4 \rightarrow H^+ + SO _4^{2-}$
$\displaystyle HSO^- _4 + H^+ \rightarrow H _2SO _4$

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen
Amphoteric species is:
  1. $Na _3PO _4$
  2. $HSO _4^-$
  3. $KOH$
  4. $HNO _3$
  5. $C _2O^{2-} _4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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

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

(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:

  1. $NO _2$
  2. $NO$
  3. $N _2O _5$
  4. $N _2O$
Reveal answer Fill a bubble to check yourself
C Correct answer
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.