Tag: chemical equilibrium and acids-bases

Quizzes (7) Questions (149)

Questions Related to chemical equilibrium and acids-bases

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following properties of a solution of $NaCl$ will not vary as the concentration of salt is increased?

  1. $pH$

  2. Density

  3. Refractive index

  4. Electrical conductivity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The presence of salts influences most physical properties of sea water (density, compressibility, freezing point, temperature of the density maximum) to some degree but does not determine them. Some properties (viscosity, light absorbtion,refractive index) are not significantly affected by salinity. (Particle and dissolved matter do affect light absorption in sea water and this influence is used in most optical applications.) Two properties which are determined by the amount of salt in the sea are conductivity and osmotic pressure.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

If a salt after rubbing with fingers gives the smell of ammonia, then the salt is:

  1. ammonium chloride

  2. sodium carbonate

  3. calcium carbonate

  4. lead sulphide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

If a salt after rubbing with fingers, gives the smell of ammonia, then the salt may be ammonium chloride.
After rubbing, due to warming, ammonium chloride may decompose to give ammonia and hydrogen chloride.
$\displaystyle NH _4Cl \xrightarrow {warm} NH _3 + HCl$

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Many salts absorb water from the atmosphere. This property is called :

  1. hydration

  2. dehydration

  3. deliquescence

  4. efflorescence
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Deliquescent salts have strong affinity for moisture and become liquid by absorbing moisture from air. It is hygroscopic in nature e.g. calcium chloride, zinc chloride,magnesium chloride,sodium hydroxide.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which one of the following substance will be most suitable for cutting a very hard material?

  1. Silicon carbide

  2. Lead

  3. Zinc metal

  4. Sodium chloride crystal
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Silicon carbide is most suitable for cutting a very hard material.
In manufacturing processes it is used for its hardness in abrasive machining processes such as grinding, honing, water-jet cutting and sandblasting.
Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the  following methods is not used for preparing a salt?

  1. Reaction between an acid and a base

  2. Action of acid on metals

  3. Action of acid on metal oxides

  4. Dissolution of acids in water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If acid is added to water the solution that forms is very dilute and small amount of heat is released so this reaction does not produce any salt.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following salt gets hydrolyzed in aqueous solution? A salt of :

  1. weak acid and weak base

  2. strong acid and weak base

  3. weak acid and strong base

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Common kind of hydrolysis occurs when a salt of a weak acid or or weak base or both is dissolved in water. Water spontaneously ionizes into hydroxide anions and hydronium cations. The salt also dissociates into its constituent anions and cations.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Aqueous solution of sodium acetate is :

  1. neutral

  2. weakly acidic

  3. strongly acidic

  4. alkaline
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium acetate is the sodium salt of acetic acid. Acetic acid reacts with sodium carbonate or sodium hydroxide to form a basic solution of sodium acetate which acts as buffer with acetic acid.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following salt gets hydrolyzed in aqueous solution? 

  1. A salt of weak acid and weak base

  2. A salt of strong acid and weak base

  3. A salt of weak acid and strong base

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Salts, when placed in water, will often react with the water to produce $H _{3}O^+$ or $OH^-$.This is known as a hydrolysis reaction.
A salt can be made of either a weak acid and strong base(i.e., basic salt), strong acid and weak base(i.e., acid salt), or a weak acid and weak base(i.e., either neutral, acidic or basic) gets hydrolyzed in aqueous solution.
Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

A solution of sodium chloride will:

  1. turn red litmus blue

  2. turn blue litmus red

  3. turn red litmus orange

  4. not change the colour of either red or blue litmus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Litmus paper can be used as an indicator to know whether a given substance is acidic, basic or neutral in nature.

Acidic substances turn blue litmus paper red but they have no effect on the red litmus paper.
Basic substances turn red litmus paper blue but have no effect on the blue litmus paper.
On the other hand, neutral substances have no effect on the blue as well as the red litmus paper.
Hence, the correct answer is option (D).