Free Salts and Hydrolysis MCQs with Answers

1. Which of the following is an acidic salt?

• A. NH4Cl
• B. NaCN
• C. CH,COONa
• D. K,SO,

Explanation: NH4Cl is a strong acidic salt because it form by strong acid HCl and ammonia

2. NaHSO4 is a _ salt

• A. Normal
• B. Acidic
• C. Basic
• D. Amphoteric

Explanation: The explanation for this question will be added soon.

3. Soda ash has the chemical formula:

• A. NaHCO3
• B. NaCO3
• C. Na2CO3
• D. Ca(OH)2

Explanation: The explanation for this question will be added soon.

4. A solid compound dissolves readily in water to give a weakly alkaline solution. On evaporation of the water, X was recovered unchanged. Which one of the following could be X?

• A. CH3 NH3 Cl
• B. CH3 O- Na+
• C. C6H5 O-Na+
• D. C6H5NH2
• E. H2NCH2CO2H

Explanation: The sodium salt of phenol, which is weakly acidic. When dissolved in water, it would give a weakly alkaline solution due to the hydrolysis of the phenoxide ion. On evaporation, we would recover the original compound unchanged.

5. Addition of 2% gypsum in cement leads to:

• A. Hydration
• B. Hydrolysis
• C. Preventing of rapid hardening
• D. All of the above options are correct

Explanation: During the grinding there is added about 2% of gypsum which prevents the cement from hardening too rapidly.The addition of gypsum increases the setting time of cement.

6. Which is the correct formula of ammonium carbamate?

• A. H2NCONH2
• B. NH4COONH4
• C. H2NCOONH2
• D. NH2COONH4

Explanation: Ammonium carbamate is a salt formed by the reaction of ammonia with carbon dioxide or carbamic acid. It has formula [NH₄][H₂NCO₂].The reaction for its formation is 2NH 3 + CO 2 → [NH 2CO 2][NH 4]

7. Substances dissolved in water react better because :

• A. Water brings them close
• B. Water helps them in bonding
• C. Water dissolve them in ions
• D. Water reacts with them

Explanation: When substances dissolve in water, they often undergo a process called hydration, where the water molecules surround and separate the individual particles of the substance, resulting in the formation of ions. This process is known as dissociation or ionization. Water has a polar molecular structure, meaning it has a slightly positive charge on one end (hydrogen) and a slightly negative charge on the other end (oxygen). This polarity allows water molecules to interact with charged particles (ions) and polar molecules by forming hydrogen bonds.

8. Which compound is formed when Ammonium hydroxide is added to silver chloride?

• A. [Ag(NH3)2]Cl
• B. [Ag(NH3)]Cl
• C. [Ag(NH3)4]Cl
• D. [Ag(NH3)6]Cl

Explanation: When ammonium hydroxide is added to silver chloride, the silver chloride dissolves in the ammonia to form a diamine complex: [Ag(NH3)2]Cl. This occurs because ammonia acts as a ligand, donating a pair of electrons to silver ions, forming a stable complex. The correct option, [Ag(NH3)2]Cl, reflects this complex formation. Other options like [Ag(NH3)]Cl, [Ag(NH3)4]Cl, and [Ag(NH3)6]Cl are incorrect as they suggest incorrect stoichiometries and coordination numbers that do not occur in this reaction.

9. Which one of the following salts will produce an alkaline solution when dissolved in water?

• A. NH4Cl
• B. NaNO3
• C. Na2CO3
• D. Na2SO4

Explanation: The correct answer is Na2CO3. Sodium carbonate forms an alkaline solution because it undergoes hydrolysis in water, releasing hydroxide ions (OH-) which increase the pH. In contrast:NH4Cl forms an acidic solution due to ammonium ions generating hydronium ions.NaNO3 remains neutral as neither ion affects pH significantly.Na2SO4 also results in a neutral solution for similar reasons to NaNO3.

10. The compound used in borax bead test for the detection of basic redicals to form colored bead is:

• A. H2BO2
• B. (C2H5)3BO3
• C. Ca2B6O115H2O
• D. Na2B4O710H2O

Explanation: Per one molecule of borax, there are 10 molecules of water of crystallization. Hence, metaborate is formed in the borax bead test.