Tag: some useful compounds in everyday life

Questions Related to some useful compounds in everyday life

When bleaching powder undergoes auto-oxidation, the change in oxidation state is:

  1. $+1 \ to +5$

  2. $-1\  to\  0$

  3. $+1 \ to +3$

  4. $-1\  to +3$


Correct Option: A
Explanation:

$6Ca(OCl) _2 \rightarrow 6Ca(ClO _3) _2 + 5CaCl _2$

On treating bleaching powder with ethyl alcohol it gives chloroform.

  1. True

  2. False


Correct Option: A
Explanation:

${ CaOCl } _{ 2 }+{ C } _{ 2 }{ H } _{ 5 }OH\rightarrow { CHCl } _{ 3 }+Ca{ \left( OH \right)  } _{ 2 }$

Bleaching powder is obtained by the reaction of $Cl _{2}$ with:

  1. dilute solution of $Ca[OH] _{2}$

  2. concentrated solution of $Ca[OH] _{2}$

  3. dry $CaO$

  4. dry slaked lime


Correct Option: B
Explanation:

$2Cl _2 + 2Ca(OH) _2(conc.) \rightarrow Ca(OCl) _2 + CaCl _2 + 2H _2O$

State whether the given statement is true or false:

Bleaching powder contains about 50 % available chlorine.

  1. True

  2. False


Correct Option: B
Explanation:

Calcium hypochlorite is a relatively stable compound and has a greater available chlorine than sodium hypochlorite. It strongly smells of chlorine owing to its slow decomposition in moist air.The percentage of chlorine in bleaching powder is between range 10 % to 40%.

Hence,it is false.

Available chlorine can be liberated from bleaching powder by the reaction with:

  1. $conc.H _{2}SO _{4}$

  2. $dil. H _{2}SO _{4}$

  3. $CO _{2}$

  4. $dil. HNO _{3}$


Correct Option: B,C,D
Explanation:

Available chlorine in bleaching powder is the amount of chlorine liberated by the action of dilute acids on bleaching powder.

On long standing, bleaching powder undergoes auto oxidation.

  1. True

  2. False


Correct Option: A
Explanation:

On long standingbleaching powder undergoes auto-oxidation which results in the formation of calcium chloride and calcium chlorate.


$6 CaOCl _2 \rightarrow5CaCl _2   + 6 Ca(ClO3) _2 $

Hence, the given statement is $true$

Substance $X$:
(I) reacts with $H _2S$ to produce white turbidity.
(II) changes light green solution of $FeSO _4$ into yellow colour.
(III) reacts with moisture to give pungent smelling gas.
Hence $X$ is:

  1. $KMnO _4$

  2. $K _2Cr _2O _7$

  3. $SO _2$

  4. $CaOCl _2$


Correct Option: D
Explanation:

$CaOCl _2+H _2O\rightarrow Ca(OH) _2+\underset {(\text {Pungent smelling gas})}{Cl _2}\uparrow$
$H _2S+Cl _2\rightarrow 2HCl+\underset {(\text {White turbidity})}{S}$
$\underset {(\text {Light green})}{2FeSO _4}+H _2SO _4+Cl _2\rightarrow Fe _2(SO _4) _3+2HCl$

The bleaching property of chlorine water is due to:

  1. formation of nascent oxygen

  2. formation of nascent chlorine

  3. formation of ${O} _{3}$

  4. reducing property of ${Cl} _{2}$


Correct Option: A
Explanation:
${ Cl } _{ 2 }+{ H } _{ 2 }O\rightarrow HCl+HOCl\rightarrow 2HCl+\left[ 0 \right] $
$\left[ 0 \right] $-Nascent oxygen
Chlorine water act as strong oxidizing agent because of nascent oxygen produced in water.