Chemistry · Science General

Common Chemical Compounds and Reactions

1,204 Questions

Common chemical compounds and reactions questions test your knowledge of everyday chemicals, their formulas, and their interactions. Topics include properties of acids and bases, hard water chemistry, and compounds like baking soda and plaster of paris. This section is essential for general science preparation.

Acids and basesPlaster of parisHard water chemistryCommon chemical formulasEveryday chemical reactions

Common Chemical Compounds and Reactions Questions

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

Chloride which is insoluble in water is :

  1. sodium chloride

  2. potassium chloride

  3. mercurous chloride

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

Chloride salts include sodium chloride (common salt), potassium chloride, calcium chloride, and ammonium chloride. Most chloride salts are readily soluble in water, but mercurous chloride (calomel) and silver chloride are insoluble, and lead chloride is only slightly soluble.

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 salts when dissolved in water would give acidic solution(s)?

  1. $Na _2SO _4$
  2. $(NH _4) _2SO _4$
  3. $CH _3COONa$
  4. $KCI$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ammonium sulfate reacts with water to form sulfuric acid which is highly acidic in nature as it completely dissociates to give hydrogen ions.

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

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

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

All  salts  are:

  1. strong electrolytes

  2. weak electrolytes

  3. non electrolytes

  4. either weak or strong electrolyte
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
As, substances that give ions when dissolved in water are called $electrolytes$.They can be divided into acids, bases and salts, because they all give ions when dissolve in water. 
$Strong$ $electrolytes$ completely ionize when dissolve in water, and no neutral molecules are formed in solution.
Example - $NaCl$, $HNO _{3}$ etc.

As we know, chemically, a salt is an ionic compound as it is composed of two oppositely charged ions - cation and anion. Due to the presence of ions, they are good conductors of heat and electricity in a molten state and in solutions.
So, all salts are strong electrolytes as they completely dissolve in water and dissociates into their component ions.

Hence, option $A$ is correct.
Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

A salt is a general name given to the chemical produced during _______ reaction between an acid and a base

  1. decomposition

  2. neutralization

  3. displacement

  4. double decomposition
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A salt is a general name given to the chemical produced during the neutralization reaction between an acid and a base.

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

 A student is performing an experiment where a blue salt is being heated to dryness in order to determine the percent of water in the salt. Which pieces of laboratory equipment would be used to help determine this percentage?
 i. A crucible and cover
 ii. Tongs
iii. A triple beam balance 

  1. ii only

  2. iii only

  3. i and iii only

  4. ii and iii only

  5. i. ii and iii
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

In this experiment, a known mass of hydrated copper(II) sulfate is heated to remove the water of crystallization and then weigh into it between 2 g and 3 g of hydrated copper(II) sulphate.A deep blue copper compound is made white through the addition of heat.So the apparatus needed is crucible,cover,tongs and triple beam balance.

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

$MgC{l} _{2}$ and $NaCl$ are both salts that are used to treat roads. Which salt will have the greatest effect on the freezing point and why?

  1. NaCl because i = 2

  2. MgCl2 because i = 3

  3. MgCl2 because i = 2

  4. NaCl because i = 3

  5. Both salts would have the same effect
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Addition of salt on roads is used to melt the ice, as this causes the lowering of the freezing point of the ice. Hence, freezing point of the ice due to the addition of the salt decreases the freezing point lesser than the $0^oC$.
Which can not be obtained easily , hence ice melts.
Now , as per formula
$ \Delta T _f = i k _f m$
Here , $i = $Vant Hoff's Factor.
which depends upon the number of dissociated ions, more the ions are dissociated from a single formula unit, more will be value of the $i$.
and $i \propto \Delta T _f$
hence , this means higher the value of $i$ , more will be lowering of the freezing point.
So here the (B) $MgCl _2$ is used , which has $i = 3$.

Multiple choice botany adaptation plant adaptation adaptation in plants plant habitat importance and classification of angiosperms aquatic plant adaptations pollination through water life in water

Crystal sand found in Atropa cells is made of

  1. Calcium oxalate

  2. Calcium carbonate

  3. Silica

  4. Silica and iron
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
  • Calcium oxalate occurs in the form of a mass of crystals around a cellulosic core in few plants.
  • Crystal sand is the calcium oxalate deposition in cells in the form of powdery mass and is seen in Atropa.
  • So, the correct answer is 'Calcium oxalate'.
Multiple choice botany adaptation plant adaptation adaptation in plants plant habitat importance and classification of angiosperms aquatic plant adaptations pollination through water life in water

Raphides are formed of

  1. Calcium oxalate

  2. Calcium carbonate

  3. Sodium chloride

  4. Sodium carbonate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
  • Calcium oxalate occurs in the form of a mass of crystals around a cellulosic core in few plants.
  • Calcium oxalate crystals occur in the form of needle-shaped in few plant cells and are called raphides.
  • Eg- Water hyacinth.
  • So, the correct answer is 'Calcium oxalate'.