Tag: salts and their classification

Questions Related to salts and their classification

Which of the following does NOT form an acidic salt?

salts salts and their classification acids, bases and salts chemistry

  1. Phosphoric acid

  2. Carbonic acid

  3. Hydrochloric acid

  4. Sulphuric

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Correct Option: B

Lime water + sulphuric acid $\rightarrow$

salts salts and their classification acids, bases and salts chemistry

  1. Heat + Calcium sulphate

  2. Water + Heat

  3. Calcium sulphate + Water + Heat

  4. None of the above

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Correct Option: C
Explanation:

Lime water/calcium hydroxide $Ca(OH) _2$ is a strong base and sulphuric acid $H _2SO _4$ is a strong acid as they undergo complete dissociation in solution.

When acid and base react with each other, the base neutralizes the acid, leading to the formation of salt and water.
This reaction is known as neutralization reaction and it is exothermic in nature (since heat is released due to formation of new bonds in the reaction).
Thus, more stronger the acid and the base, more amount of heat is released.
$Ca(OH) _2 + H _2SO _4 \rightarrow CaSO _4+2H _2O + Heat$.
Hence, the correct answer is option (C).

Which technique produces a compound which is not soluble in water?

salts salts and their classification acids, bases and salts chemistry

  1. Conductivity

  2. Calorimetry

  3. Precipitation

  4. Spectrophotometry

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Correct Option: C
Explanation:

A reaction occurs when you mix two aqueous solutions. This is when you will find out whether a precipitate will form or not. A precipitate forms if the product of the reaction is insoluble in water.

Precipitation occurs when cations and anions in the aqueous solution combine to form an insoluble ionic solid called a precipitate.
Conductivity is the property to conduct electricity, calorimetry is the process of measuring the heat of chemical reactions and spectrophotometry is the measurement of reflection or transmission properties of the material as a function of wavelength.
Since precipitation produces a compound which is not soluble in water, the correct answer is the option (C).

When the aqueous solution of silver nitrate and sodium chloride are mixed, a________ precipitate is immediately formed.

salts salts and their classification acids, bases and salts chemistry

  1. yellow

  2. white

  3. red

  4. black

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Correct Option: B
Explanation:

When silver nitrate $(AgNO _3)$ reacts with sodium chloride $(NaCl)$ a white precipitate of silver chloride $(AgCl)$ is formed which is highly insoluble in water, along with formation of sodium nitrate $(NaNO _3)$.

Since $(AgCl)$ is insoluble in water it will precipitate out and $(NaNO _3)$ is soluble in water so it will remain dissolved in the mixture. This reaction is an example of double displacement reaction and it occurs as follows:-
$AgNO _3\ +\ NaCl \rightarrow AgCl\ +\ NaNO _3 $
Hence, the correct answer is the option (B).

${ H } _{ 3 }{ PO } _{ 4 }$ 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)

salts salts and their classification acids, bases and salts chemistry

  1. 100 mL

  2. 200 mL

  3. 80 mL

  4. 300 mL

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Correct Option: B
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

Which of the following has the highest melting point ?

salts salts and their classification acids, bases and salts chemistry

  1. $BeCl _2$

  2. $LiCl$

  3. $AlCl _3$

  4. $NaCl$

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Correct Option: D
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 $Cl$.

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

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

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

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

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Correct Option: B