Tag: oxoacids of halogens

Questions Related to oxoacids of halogens

On boiling an aqueous solution of $KClO _{3}$ with $I _{2}$ the products obtained are:

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

  1. $KIO _{3} + Cl _{2}$

  2. $KCl + I _{2}O _{5}$

  3. $KIO _{4} + Cl _{2}$

  4. none of the above

Show answer
Correct Option: D
Explanation:

$KClO _3 + 6HCl + I _2 \rightarrow 2ICl _3 + KI + 3H _2O$ 

Bleaching action of $CaOCl _2$ is due to :

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

  1. Nascent oxygen

  2. $Ca$

  3. $Cl$

  4. $HCl$

Show answer
Correct Option: A,C
Explanation:

Calcium oxychloride ($CaOCl _2$) is known as bleaching powder. When it is treated with excess of dilute acids, chlorine is evovled which is responsible for the bleaching action of bleaching powder. Due to the evolution of nacent oxygen, it acts an an oxidising and bleaching agent.

Match the correct use for the following chemicals:

$ KClO 3 $ is used ______.

$ KClO _4 $ is used as ________.

$ Mg(ClO _4) _2 $ is used as ________.

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

  1. $ KClO _3 $- Explosive

  2. $ KClO _4 $- Fireworks and flares

  3. $ Mg(ClO _4) _2 $- Dry batteries

  4. $ KClO _3 $- Fireworks and flares

  5. $ Mg(ClO _4 ) _2$- Explosive

Show answer
Correct Option: A,B,C
Explanation:

$ KClO _3 $- Explosives.May explode under prolonged exposure to heat or fire.


$ KClO _4 $- Fireworks and flares. It is an oxidizer in the sense that it exothermically transfers oxygen to combustible materials, greatly increasing their rate of combustion relative to that in air.


$ Mg(ClO _4) _2 $- Dry batteries.It is drying agent for gases. It can remove water from gases (with no organic contaminants) at the rate of 0.001mgwater/l.

Choose the correct statements:

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

  1. The anyhdride of $HOCl$ is $Cl _2O$.

  2. The anyhdride of $HClO _2$ is $ClO _2$.

  3. The anyhdride of $HClO _3$ is $Cl _2O _6$.

  4. The anyhdride of $HClO _4$ is $Cl _2O _7$.

  5. The anyhdride of $HClO _3$ is $Cl _2O _3$.

Show answer
Correct Option: A,B,C,D
Explanation:

The anyhdride of $HOCl$ is $Cl _2O$.
The anyhdride of $HClO _2$ is $ClO _2$.
The anyhdride of $HClO _3$ is $Cl _2O _6$.
The anyhdride of $HClO _4$ is $Cl _2O _7$.
Anhydrides on reaction with water will give you corresponding acid.

Choose the correct oxidation states of Chlorine in species: 

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

  1. (a) $\displaystyle { HOCl }- +1$

  2. (b) $\displaystyle { HOCl }O- +3$

  3. (c) $\displaystyle { HOBr }- +3$

  4. (d) $\displaystyle { HOBrO } _{ 2 }- +5$

  5. (e) $\displaystyle { HOIO } _{ 3 }- +7$

  6. (f) $\displaystyle { HOClO } _{ 3 }- +5$

  7. None of the above

Show answer
Correct Option: A,B,D,E
Explanation:

(a) hypochlorous acid +1
(b) chlorous acid +3
(c) hypobromous acid +1
(d) bromic acid +5
(e) periodic acid +7
(f) perchloric acid +7

Select the incorrect order(s) among the following :

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

  1. $ClO^- < BrO^- < IO^-$ - disproportionation

  2. $ClO _4^- < BrO _4^- < lO _4^-$ - oxidising power

  3. $HClO < HClO _2 < HClO _3 < HClO _4$ - acid strength

  4. $HOCl > HOI > HOBr$ - acid strength

Show answer
Correct Option: B,D
Explanation:

1) The reduction potential values are as follows:
$ClO _4^-: 1.19\ V$,
$BrO _4^-: 1.65\ V$,
$BrO _4^-: 1.74\ V$.
So, the order of oxidising power is: $ClO _4^- < IO _4^- < BrO _4^-$.
2) The correct order of acidic strength is: $HOCl < HOBr < HOI$. As the electronegativity of halogens increases, the acidic character also increases.

The reaction, $3ClO _{(aq.)}^-\rightarrow ClO _{3(aq.)}^-+2Cl^- _{(aq.)}$ is an example of :

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

  1. oxidation reaction.

  2. reduction reaction.

  3. disproportionation.

  4. decomposition reaction.

Show answer
Correct Option: C
Explanation:
  1. Disproportionation is a specific type of redox reaction in which a species is simultaneously reduced and oxidised to form two different products.
    Here the $ClO^{-}$ is simultaneously reduced and oxidised to form two different products.

    Hence option C is correct.

When bleaching powder is treated with mineral acids,the gas evolved is:

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

  1. $Cl _2$

  2. $O _2$

  3. $H _2$

  4. none of these

Show answer
Correct Option: A
Explanation:

When bleaching powder is treated with mineral acids ${ Cl } _{ 2 }$ gas evolved

When Halogens are treated with hot and conc. alkalis,major products formed are:

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

  1. Hypohalite

  2. Halite

  3. Halate

  4. Halide

Show answer
Correct Option: C,D
Explanation:

Halogen are treated with hot and conc. alkalis, major products formed are Halate and halide.

When bromate salt are reacted with fluorine in alkaline solution,which salt is formed?

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

  1. Bromide

  2. Bromous

  3. Hypobromous

  4. Perbromate

Show answer
Correct Option: D
Explanation:
(bromate salt)  ${ Br }{ O } _{ 3 }^{ - }+{ F } _{ 2 }\left( g \right) +{ 2OH }^{ - }\longrightarrow { Br }{ O } _{ 4 }^{ - }+{ H } _{ 2 }O+2{ F }^{ - }$  (perbromate)
Perbromate is the sluggish oxidant. Although it is more active than the Perchlorate ion in the agneous solution.