Tag: oxoacids of halogens

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Questions Related to oxoacids of halogens

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

When slaked lime is treated with chlorine, a compound is formed. Which of the following is correct about that compound? 

  1. It is used in bleaching cotton.

  2. It is used as disinfectant.

  3. It is a halide.

  4. It is used for sterilization of water.
Reveal answer Fill a bubble to check yourself
A,B,D Correct answer
Explanation

Calcium hydroxide react with chlorine to give calcium hipochlorite, calcium chloride and water. Calcium hipochlorite which is formed in the reaction is used as bleaching agent, disinfevtant and in the sterilization process.

$2Ca(OH) _2 + 2Cl2 \rightarrow Ca(ClO) _2 + CaCl _2 + 2H _2O$.

Hence option A,B,C are correct.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

The weakest $Cl-O$ bond is found in :

  1. $ClO _{4}^{-}$
  2. $ClO _{2}^{-}$
  3. $ClO^{-}$
  4. $ClO _{3}^{-}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The anions given are conjugate bases of acids. According to Lowry Bronsted concept, a strong acid has weak conjugate base and a weak acid has a strong conjugate base. These anions are stabilised to greater extent, it has lesser attraction for proton and therefore, will behave as weaker base (lesser tendency for the reaction to go in backward direction). Consequently, the corresponding acid will be strongest because weak conjugate base has strong acid and strong conjgate base has weak acid and vice versa. The charge stabilization increases in the order : $ClO^- < ClO _2^- < ClO _3^- < ClO _4^-$. This means that $ClO^-$ will have minimum stability and therefore, will have maximum attraction for $H^+$. In other words $ClO^-$ will be strongest base and so its conjugate acid HClO will be the weakest acid.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Which one is most stable to heat :

  1. $HClO$
  2. $HClO _{2}$
  3. $HClO _{3}$
  4. $HClO _{4}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The thermal stability of the oxyacids of halogens increases with increase in the oxidation state of halogen or with increase in the number of oxygen atoms.
 This is due to involvement of more electrons in the formation of sigma and pi bonds. The multiplicity of the Cl-O bond increases.
Thus the increasing order of the thermal stability is $HClO <HClO _2 <HClO _3<HClO _4$. Thus, $HClO _4$ is most stable to heat.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Hypervalent ion is/are :

  1. $SO _3^{2-}$
  2. $PO _4^{3-}$
  3. $SO _4^{2-}$
  4. $ClO _4^{-}$
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation
Hypervalent molecule -
The hypervalent molecule is a molecule that contains one or more main group elements apparently bearing more than eight electrons in their valence shells.

 Explanation -
A. Valence electrons available in $(SO _3)^{2-}$ => 8
B. Valence electrons available in $(PO _4)^{3-}$ => 10
C. Valence electrons available in $(SO _4)^{2-}$ => 12
D. Valence electrons present  in $(ClO _4)^-$ => 14

Hence B, C, D are hypervalent compounds.
Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Which one of the following oxoacids of chlorine is the least oxidising in nature ?

  1. $ HClO $
  2. $HClO _2 $
  3. $ HClO _3 $
  4. $HClO _4$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$HClO _4$ is the strongest oxidizing agent as the oxidation number of chlorine in $HClO _4$ is +7 and it can't afford to lose any more electron.


It can only gain the electrons which result in oxidation of other species.

Hence, the correct option is $D$

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Out of the chloric acid ($\displaystyle { HClO } _{ 3 }$) and perchloric acid ($\displaystyle { HClO } _{ 4 }$), $\displaystyle { HClO } _{ 4 }$ is more stable.


State whether the above statement is true or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Perchloric acid (HClO4) is more stable than chloric acid (HClO3) because the perchlorate ion (ClO4-) has greater resonance stabilization due to the higher number of oxygen atoms distributing the negative charge.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Which of the following is the correct statement? 

  1. $ SO _2 $ is anhydride of sulphuric acid
  2. $ NO _2 $ is anhydride of nitric acid
  3. $ Cl _2O _7 $ is anhydride of perchoric acid
  4. $ P _2O _5 $ is anhydride of orthophosphorus acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
$Cl _2​O _7​+H _2​O⟶2HClO _4​$

Thus $Cl _2​O _7​$ is an anhydride of perchloric acid.

Option C is correct.
Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Select the correct statement(s) :

  1. The overlap become better when the overlapping orbitals have comparable energy.
  2. The other of increasing tendency of polymerizations $SiO^{4-} _{4}\, >\, PO^{3-} _{4}\, >\, SO^{2-} _{4}\, >\, ClO^{-} _{4}$.
  3. With the increase in positive oxidation state the energy of the 3d-orbitals gradually decreases and it favours the $\pi$-bonding interaction.
  4. The system where the $\pi$ bonding is not effective, the stabilization is attained through the single bonded structure i.e. through the polymerization.
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

The overlap become better when the overlapping orbitals have comparable energy. The extent of overlap between orbitals with huge energy difference is insignificant.

The other of increasing tendency of polymerizations $SiO^{4-} _{4}\, >\, PO^{3-} _{4}\, >\, SO^{2-} _{4}\, >\, ClO^{-} _{4}$. This is the same order in which the electronegativity of the central atom increases.

With the increase in positive oxidation state the energy of the 3d-orbitals gradually decreases and it favors the $\pi$-bonding interaction.

The system where the $\pi$ bonding is not effective, the stabilization is attained through the single bonded structure, i.e., through the polymerization. An example is polymer containing $SiO^{4-} _{4}$ tetrahedra.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

The following acids have been arranged in the order of decreasing acid strength. Identify the correct order-
ClOH(I)            BrOH(II)          IOH(III)

  1. I > II > III

  2. II > I > III

  3. III > II > I

  4. I > III > II
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Higher the I.E, higher the acidic strength of hypohalus acid (hydroxides)

As we move from top to bottom in halogens the I.E will be decreased,so the acidity will be decreased.
The correct oreder of acidity is I > II > III
Hence option A is correct.