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Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Bleaching powder slowly decomposes to form:

  1. $CaCl _2+Ca(ClO _3) _2$
  2. $CaO+Cl _2$
  3. $CaCl _2+Ca(OCl) _2$
  4. $CaCO _3+Cl _2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When exposed to air, bleaching powder gives a smell of chlorine. This is because bleaching powder reacts with carbon dioxide from the atmosphere to produce calcium carbonate and chlorine.

$Ca(OCl) _2 +CO _2 \rightarrow CaCO _3 +Cl _2$

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

The average oxidation state of chlorine in bleaching power is :

  1. -1

  2. +1

  3. zero

  4. -2 as well as +2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In bleaching powder, $Ca(OCl)Cl$, the two $Cl$ atoms are in different oxidation states i.e., one $Cl^–$ having oxidation number of –1 and the other as $OCl^–$ having oxidation number of +1.


Hence, the average oxidation state of chlorine in bleaching powder is zero.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Which one of the following processes does not occur during formation of $CH{ Cl } _{ 3 }$ from ${ C H } _{ 3 }OH$ and bleaching powder ?

  1. Hydrolysis

  2. Oxidation

  3. Reduction

  4. Chlorination
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The process that does not occur during the formation of $CHCl _3$ from $CH _3OH$ and Bleaching Powder is REDUCTION PROCESS.
In $CHCl _3$ oxidation state of carbon is +2 and in methanol oxidation state of carbon is-2. This is reduction.
Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Action bleaching poweder on ethyyl alcohol gives?

  1. Chloroform

  2. Dichloro methane

  3. Trichloro ethane

  4. Ethylene chloride
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The reactions involved are-

$CaOCl _2 + H _2O \rightarrow Ca(OH) _2 + Cl _2$

$C _2H _5OH + [O] \rightarrow CH _3CHO$

$CH _3CHO + Cl _2 \rightarrow CCl _3HO$

$CCl _3CHO + Ca(OH) _2 \rightarrow CHCl _3 + (HCOO) _2Ca$


Hence the product formed is having Chloroform and the correct option is A.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Bleaching properties of bleaching powder are due it its:

  1. Oxidizing properties

  2. Reducing properties

  3. Basic properties

  4. Disinfecting properties
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action.

Chlorine reacts with water to form hydrochloric and hypochlorous acids.

$Cl _2 + H _2O \rightarrow HCl + HClO$

Hypochlorous acid is unstable, and it easily dissociates to form nascent oxygen.

$HClO \rightarrow HCl + [O]$

Nascent oxygen is a more powerful oxidising agent. Its formation is responsible for the bleaching nature of chlorine in the presence of moisture.

Hence option A is correct answer.

Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Oxidation number of $Cl$ in ${ CaOCl } _{ 2 }$ (bleaching powder) is:

  1. zero, since it contains ${ Cl } _{ 2 }$
  2. $-1$, since it contains ${ Cl }^{ - }$
  3. $-1$, since it contains ${ ClO }^{ - }$
  4. $+1$ and $-1$ since it contains ${ ClO }^{ - }$ and ${ Cl }^{ - }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
In bleaching powder,$CaOCl _2,$ the two $Cl$ atoms are in different oxidation states i.e.,one $Cl$ atom having oxidation number of $-1$ and the other as $OCl^-$ having oxidation number of $+1$.
Therefore,$+1$ and $-1$ Since it contains $ClO^-$ and $Cl^-$
Ans is option $D$
Multiple choice chemistry substances in common use chemical from common salt compounds of carbon some useful compounds in everyday life

Bleaching powder is disinfectant for purification of water when water born germs are killed. But disinfectant activity is destroyed. It is due to its disproportionation into:

  1. $ CaCl _2$ and $Cl _2 $
  2. $ CaCl _2$ and $Ca(ClO _3) _2 $
  3. $ CaO$ and $Cl _2 $
  4. $ CaO, Cl _2$ and $CaCl _2 $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Bleaching powder is disinfectant for purification of water when water born germs are killed. But disinfectant activity is destroyed because of the degradation of high grade of bleaching powder.
These include disproportionation to give $Ca(ClO _3) _2$ and $CaCl _2$, and with the evolution of $Cl _2$ or $O _2$ depending on the presence or absence of water.

Option B is the correct answer.