Chemistry

Chemical Reactions and Equations

684 Questions

Chemical reactions and equations form a foundational chemistry topic where students identify reaction products, balance chemical formulas, and classify reaction types. It covers critical mechanisms like Markovnikov's rule, precipitation, and endothermic or exothermic processes. These questions are highly common in general science sections of state and central government competitive exams.

Endothermic reactionsPrecipitation reactionsDehydrohalogenation of alkyl halidesChemical equation balancingReaction product identification

Chemical Reactions and Equations Questions

Multiple choice

Conversion of ethene in to ethane is an example of

  1. addition reaction.

  2. substitution reaction.

  3. oxidation reaction.

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

Converting ethene (an unsaturated hydrocarbon) to ethane (a saturated hydrocarbon) involves adding hydrogen across the double bond. This is a classic addition reaction.

Multiple choice

Which of the following can be excluded from the category of the electrophilic addition reaction?

  1. A halogenation reaction

  2. A hydrohalogenation reaction

  3. The Michael reaction

  4. The oxymercuration reaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Michael reaction or Michael addition is the nucleophilic addition of a carbanion or another nucleophile to an alpha, beta unsaturated carbonyl compound. It belongs to the larger class of conjugate additions.

Multiple choice

The ----------------- compound is generally used to carry out nucleophilic substitution reactions.

  1. Chlorofluoromethane

  2. Chloroform

  3. Chloromethane

  4. tert-Butyl chloride
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

tert-Butyl chloride is a colourless, liquid organic compound at room temperature. The compound is flammable and volatile, and its main use is as a starting molecule to carry out nucleophilic substitution reactions, to produce different substances, ranging from alcohols to alkoxide salts.

Multiple choice

Birch reduction process is associated with

  1. 1,4-Cyclohexadiene

  2. Cyclohexane

  3. Cyclohexanol

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

1,4-Cyclohexadiene is a highly flammable cycloalkene that occurs as a colourless clear liquid. 1,4-Cyclohexadiene and related compounds may be prepared from benzene using lithium or sodium in liquid ammonia, this process being known as a Birch reduction.

Multiple choice

Ozone essentially behaves as a

  1. dehydrating agent

  2. catalytic agent

  3. powerful oxidising agent

  4. a reducing agent

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ozone essentially behaves as a powerful oxidising agent.

Multiple choice

Directions: The following question has four choices out of which ONLY ONE is correct.

Which among the following is not a zero order reaction?

  1. Photochemical reaction between hydrogen and chlorine

  2. Decomposition of N2O on hot platinum surface

  3. Iodinations of acetone in presence of H+ ions

  4. Thermal decomposition of chlorine monoxide
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Thermal decomposition of dichlorine monoxide is a second order reaction. 2Cl2O → 2Cl2 + O2

Multiple choice

The diazonium salt decomposes as, C6H5N2+Cl- $\to$ C6H5Cl + N2. At 00 C, the evolution of nitrogen becomes two times faster when the initial concentration of the salt doubles. Therefore, it is a

  1. first order reaction

  2. second order reaction

  3. third order reaction

  4. zero order reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Since the evolution of nitrogen becomes two times faster when the initial concentration of the salt is doubled, so it is a first order reaction.

Multiple choice

Which of the following equations is balanced?
  1. $KNO_3$ $\to$ $KNO_2$ + $O_2$
  2. $2KNO_3$ $\to$ $2KNO_2$ + O
  3. $2KNO_3$ $\to$ $KNO_2$ + $2O_2$
  4. $2KNO_3$ $\to$ $2KNO_2$ + $O_2$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In option (4), number of atoms on both the sides of the equation is the same.