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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 p-block elements oxides of elements simple oxides oxygen

Which of the following constitutes a set amphoteric species.?

  1. $H _3O^+, H _2PO^- _4, HCO^- _3$
  2. $H _2O, HPO^{2-} _4, H _2PO^- _2$
  3. $H _2O, H _2PO^- _3, HPO^{2-} _4$
  4. $HC _2O^- _4, H _2PO^- _4, SO^{2-} _4$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Amphoteric species can act as both acids and bases. H2O, H2PO3-, and HPO4(2-) can all donate or accept protons depending on the reaction environment.

Multiple choice chemistry p-block elements oxides of elements simple oxides oxygen

Which of the following oxides is nuetral?

  1. CO
  2. $SnO _2$

  3. ZnO
  4. $SiO _2$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Neutral oxides show neither basic nor acidic properties and hence do not form salts when reacted with acids or bases.
  • Carbon and oxygen together have a total of 10 valence electrons in carbon monoxide. To satisfy the octet rule for the carbon, the two atoms form a triple bond, with six shared electrons in three bonding molecular orbitals, rather than the usual double bond found in organic carbonyl compounds. Since four of the shared electrons come from the oxygen atom and only two from carbon, one bonding orbital is occupied by two electrons from oxygen, forming a dative or dipolar bond. This causes a $C\leftarrow O$ polarization of the molecule, with a small negative charge on carbon and a small positive charge on oxygen. Overall the molecule is neutral.
  • Hence option A is correct answer.
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.