Tag: acids, bases and salts

Quizzes (14) Questions (84)

Questions Related to acids, bases and salts

Multiple choice salts salts and their classification acids, bases and salts chemistry

${ H } _{ 3 }{ PO } _{ 4 }$ is a tribasic acid and one of its salt is $Na{ H } _{ 2 }{ PO } _{ 4 }$. What volume of 1M NaOH solution should be added to 12g $Na{ H } _{ 2 }{ PO } _{ 4 }$ to convert it into $Na _{ 3 }{ PO } _{ 4 }$? (at.wt of P=31)

  1. 100 mL

  2. 200 mL

  3. 80 mL

  4. 300 mL
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$NaH _2PO _4$ + $ 2 NaOH $ $ \rightarrow Na _3PO _4 + H _2O $

From the above reaction we can say that,
1 mol of $NaH _2PO _4$ reacts with 2 mol of NaOH.
Molar mass of $NaH _2PO _4$  = 120 g / mol
12g of $NaH _2PO _4$ contains = 0.1 mol
So the number of moles of NaOH required = 0.2 mol
Molarity of NaOH = 1M
1 mol = 1000 ml
0.2 mol = ?
So, the volume of 1M NaOH solution = 200 ml

Multiple choice salts salts and their classification acids, bases and salts chemistry

Which of the following has the highest melting point ?

  1. $BeCl _2$
  2. $LiCl$
  3. $AlCl _3$
  4. $NaCl$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium and magnesium chlorides are solids with high melting and boiling points because of the large amount of heat which is needed to break the strong ionic attractions.
$NaCl$ having the highest melting point as the ionic bond is too strong between $Na$ and $Cl$.

Multiple choice salts salts and their classification acids, bases and salts 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?

  1. $x=y$
  2. $x=0.5y$
  3. $x=0.4y$

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
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 $x=0.5y$
Multiple choice salts salts and their classification acids, bases and salts chemistry

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

  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. ${\text{Al}}{\left( {{\text{CN}}} \right) _{\text{3}}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

CH3COOK is a salt of a weak acid (acetic acid) and a strong base (potassium hydroxide). In aqueous solution, the acetate ion undergoes hydrolysis to form OH- ions, making the solution basic. The other options involve salts of strong acids or weak bases, which result in acidic or neutral solutions.

Multiple choice salts salts and their classification acids, bases and salts chemistry

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:

  1. $NaN{O _3},NaBr$
  2. $NaBr,NaN{O _3}$
  3. $NaBr,NaN{O _2}$
  4. $NaN{O _{2,}}NaBr$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bromide salts (NaBr) react with conc. H2SO4 to produce reddish-brown bromine vapors. Nitrates (NaNO3) react with conc. H2SO4 to produce reddish-brown NO2 gas upon heating. Since A reacts with dil. HCl, it must be the bromide (as nitrates do not react with dil. HCl).

Multiple choice salts salts and their classification acids, bases and salts chemistry

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

  1. $K^{+}$
  2. $Cl^{-}$
  3. $Ba^{2+}$ and $SO _{4}^{-2}$
  4. Both $A$ and $B$
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice salts salts and their classification acids, bases and salts chemistry

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]

  1. 2

  2. 3

  3. 4

  4. 5
Reveal answer Fill a bubble to check yourself
B Correct answer
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 $(B)$.

Multiple choice salts salts and their classification acids, bases and salts chemistry
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].

  1. 1

  2. 2

  3. 3

  4. 4
Reveal answer Fill a bubble to check yourself
D Correct answer
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 $(D)$