Tag: chemistry

Questions Related to chemistry

Equal volumes of $1\ M$ $HCl$ and $1\ M$ $H _2SO _4$ are neutralized by dilute NaOH solution liberating $x$ kcal and $y$ kcal heat. Which of the following is correct?

salts salts and their classification acids, bases and salts chemistry

  1. $x=y$

  2. $x=0.5y$

  3. $x=0.4y$

  4. None of these

Show answer
Correct Option: B
Explanation:
Reaction involved are:
$HCl+NaOH \rightarrow NaCl+H _2O, \Delta H _1=xkcal$
$H _2SO _4+2NaOH \rightarrow Na _2SO _4+2H _2O, \Delta H _1=ykcal$
(i) acid-base neutralization reaction for HCl is represented as:
$H^++OH^- \rightarrow H _2O, \Delta H _1=xkcal$
(ii) acid-base neutralization reaction for $H _2SO _4$ is represented as:
$2H^++2OH^- \rightarrow 2H _2O, \Delta H _1=ykcal$
since reaction (ii) is twice of reaction (i), so is the enthalpies
thus $2x=y$
or $x=0.5y$

Which of the following salts is most basic in aqueous solution?

salts salts and their classification acids, bases and salts chemistry

  1. ${\text{C}}{{\text{H}} _{\text{3}}}{\text{COOK}}\,$

  2. ${\text{FeC}}{{\text{l}} _{\text{3}}}\,\,$

  3. ${\text{Pb(C}}{{\text{H}} _{\text{3}}}{\text{COOK}}{{\text{)}} _{\text{2}}}\,$

  4. ${\text{Al}}{\left( {{\text{CN}}} \right) _{\text{3}}}$

Show answer
Correct Option: A

A and B are two salts. A with dil. HCI and A and B with conc. ${H _2}S{O _4}$react to give reddish brown vapours, hence A and B respectively are:

salts salts and their classification acids, bases and salts chemistry

  1. $NaN{O _3},NaBr$

  2. $NaBr,NaN{O _3}$

  3. $NaBr,NaN{O _2}$

  4. $NaN{O _{2,}}NaBr$

Show answer
Correct Option: B

A and B are two salts. A with dil. HCI and A and B with conc. ${H _2}S{O _4}$  react  to give reddish brown  vapour, hence A and B respectively are.

salts salts and their classification acids, bases and salts chemistry

  1. $NaN{O _3},NaBr$

  2. $NaBr,NaN{O _3}$

  3. $NaBr,NaN{O _2}$

  4. $NaN{O _{2,}}NaBr$

Show answer
Correct Option: B

In the reaction, $BaCl _{2}(aq)+K _{2}SO _{4}(aq)\rightarrow BaSO _4(s)+2KCl(aq)$, which is not a spectator ion?

salts salts and their classification acids, bases and salts chemistry

  1. $K^{+}$

  2. $Cl^{-}$

  3. $Ba^{2+}$ and $SO _{4}^{-2}$

  4. Both $A$ and $B$

Show answer
Correct Option: C
Explanation:

Ions that are not involved in the formation of insoluble solid are called as spectator ions.


Therefore, $Ba^{2+}$ and $SO _{4}^{2-}$ ions form insoluble solid.

Hence they are not spectator ions.


Option C is correct.

We can obtain zinc sulphate from an active metal.

salts salts and their classification acids, bases and salts chemistry

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

$Zn+{ H } _{ 2 }{ SO } _{ 4 }(dil.)\rightarrow { ZnSO } _{ 4 }+{ H } _{ 2 }$

Which of the following methods is generally used for preparing $Zn(NO _3) _2$ salt?


1 : Neutralisation - insoluble base & dilute acid  
2 : Neutralisation - alkali & dilute acid      

3 : Simple displacement - active metal & dilute acid  
4 : Direct combination                     

5 : Precipitation [double decomposition]

salts salts and their classification acids, bases and salts chemistry

  1. 2

  2. 3

  3. 4

  4. 5

Show answer
Correct Option: B
Explanation:

Zinc metal with dilute nitric acid gives zinc nitrate.

So, simple displacement-active metal & dilute acid is the correct option for this.

$Zn+2HNO _3 \rightarrow Zn(NO _3) _2+H _2$

Hence, the correct option is $(B)$.

State which of the following methods is generally used for preparing the $FeS$ salts
1: Neutralisation-insoluble base & dilute acid.
2: Neutralisation-alkali & dilute acid.
3: Simple displacement-active metal & dilute acid.
4: Direct combination.
5: Precipitation [double decomposition].
salts salts and their classification acids, bases and salts chemistry

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: D
Explanation:


Iron(II) sulfide is obtained by heating of iron and sulfur which is a direct combination.
$Fe+S \longrightarrow FeS$


Hence, the correct option is $(D)$

State which of the following methods is generally used for preparing the $Cu(NO _3) _2$ salts.
1: Neutralisation-insoluble base & dilute acid.
2: Neutralisation-alkali & dilute acid.
3: Simple displacement-active metal & dilute acid.
4: Direct combination.           
5: Precipitation [double decomposition].
salts salts and their classification acids, bases and salts chemistry

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: C
Explanation:

Copper reacts with nitric acid to form copper nitrate.


$3Cu+8HNO _3 \rightarrow 3Cu(NO _3) _2+4H _2O+2NO$

Hence, the correct option is simple displacement-active metal & dilute acid.  


Hence, the correct option is $(C)$

The best indicator for the detection of end point in titration of a weak acid and a strong base is :

salts salts and their classification acids, bases and salts chemistry

  1. methyl orange (3 to 4)

  2. methyl red (5 to 6)

  3. bromothymol blue (6 to 6.5)

  4. bromothymol blue (6 to 7.5)

Show answer
Correct Option: D
Explanation:

BTB is a pH indicator for reactions between weak acids and bases. It is mostly used in applications that require measuring substances that have a pH near 7. It can be protonated or deprotonated appearing yellow or blue. It is bluish green in neutral solution.