Tag: chemistry

Questions Related to chemistry

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. $N _2O _5$

Show answer
Correct Option: A

Which of the following constitutes a set amphoteric species.?

chemistry p-block elements oxides of elements simple oxides oxygen

  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. $HC _2O^- _4, H _2PO^- _4, SO^{2-} _4$

Show answer
Correct Option: C

Which of the following oxides is nuetral?

chemistry p-block elements oxides of elements simple oxides oxygen

  1. CO

  2. $SnO _2$

  3. ZnO

  4. $SiO _2$

Show answer
Correct Option: A
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.

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. $N$

Show answer
Correct Option: C
Explanation:

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

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