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 chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

$N _2(g) + 3H _2(g)\overset{Fe+Mo}{\rightleftharpoons}2NH _3(g)$; Haber's process.

Mo is used as :

  1. a catalyst

  2. a catalytic promoter

  3. an oxidising agent

  4. a catalytic poison
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$NH _3$ is manufactured by Haber's process.
$N _2(g) + 3H _2(g)\overset{Fe+Mb}{\rightleftharpoons}2NH _3(g)$
In this process, pure nitrogen and hydrogen gases react in the ratio of $1:3$ by volume in $400^0C-500^0C$ temperature, $200-900$ atm pressure in presence of iron as catalyst and Mo as promoter.

Multiple choice chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

What are the missing products of the following reaction? $\displaystyle { NH } _{ 4 }Cl+{ Ca\left( OH \right)  } _{ 2 }\rightarrow \ _ \ _ \ _ +Ca{ Cl } _{ 2 }$

  1. $\displaystyle { N } _{ 2 }$
  2. $\displaystyle { NH } _{ 3 }$
  3. $\displaystyle { H } _{ 2 }O$
  4. $\displaystyle { NH } _{ 3 }+{ N } _{ 2 }$
  5. $\displaystyle { NH } _{ 3 }+{ H } _{ 2 }O$
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Calcium hydroxide reacts with ammonium chloride to give ammonia, water and calcuim chloride.

${ 2NH } _{ 4 }Cl+Ca{ (OH) } _{ 2 }\rightarrow { 2NH } _{ 3 }+{ 2H } _{ 2 }O+{ CaCl } _{ 2 }$

Multiple choice chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

In the Haber process of synthesis of $NH _3$,  which of the following statement is correct?

  1. $Mo$ acts as a catalyst and $Fe$ as a promoter
  2. $Fe$ acts as a catalyst and $Mo$ as a promoter
  3. $Fe$ acts as inhibitor and $Mo$ as a catalyst
  4. $Fe$ acts as promoter and $Mo$ as autocatalyst
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Preparation of Ammonia: 

$N _2 + 3H _2\rightarrow 2NH _3$

At high pressure about 200-250 atm, and a moderate temperature of $750K$, the reaction takes place. Removal of ammonia is done by liquefaction, In the process, iron is used as a catalyst and molybdenum as a promoter.

Multiple choice

Which of the following reactions is an example of an addition reaction?

  1. Substitution

  2. Elimination

  3. Addition

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

Addition reactions are reactions in which two or more molecules combine to form a single molecule. An example of an addition reaction is the reaction of an alkene with a hydrogen halide to form an alkyl halide.

Multiple choice

Which of the following is an example of a nucleophilic substitution reaction?

  1. SN1

  2. SN2

  3. E1

  4. E2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nucleophilic substitution reactions are reactions in which a nucleophile (an electron-rich species) attacks an electrophile (an electron-poor species) and replaces a leaving group. SN2 reactions are nucleophilic substitution reactions in which the nucleophile attacks the electrophile in a single step.

Multiple choice

Which of the following is an example of a condensation reaction?

  1. Aldol Condensation

  2. Claisen Condensation

  3. Knoevenagel Condensation

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

Condensation reactions are reactions in which two or more molecules combine to form a single molecule with the loss of a small molecule, such as water or alcohol. The Aldol Condensation is a condensation reaction in which an aldehyde or ketone reacts with an enolate ion to form a β-hydroxyaldehyde or β-hydroxyketone.

Multiple choice

Which of the following is an example of an elimination reaction?

  1. Substitution

  2. Elimination

  3. Addition

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

Elimination reactions are reactions in which two or more molecules are formed from a single molecule with the loss of a small molecule, such as water or hydrogen halide. An example of an elimination reaction is the reaction of an alkyl halide with a base to form an alkene.

Multiple choice

Which of the following is a common type of reaction intermediate?

  1. Carbocations

  2. Free radicals

  3. Carbanions

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

Carbocations, free radicals, and carbanions are all common types of reaction intermediates that are formed during the course of a chemical reaction.

Multiple choice

Which of the following is an example of an organometallic reaction?

  1. The reaction of a metallocene with an alkene.

  2. The reaction of a metallocene with a diene.

  3. The reaction of a metallocene with a carbon monoxide.

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

All of the above reactions are examples of organometallic reactions.

Multiple choice

What is the name of the reaction in which an organometallic compound inserts a carbon monoxide molecule into a carbon-carbon bond?

  1. Carbonylation

  2. Hydroformylation

  3. Alkylation

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

Carbonylation is the name of the reaction in which an organometallic compound inserts a carbon monoxide molecule into a carbon-carbon bond.

Multiple choice

What is the name of the reaction in which an organometallic compound inserts a hydrogen molecule into a carbon-carbon bond?

  1. Carbonylation

  2. Hydroformylation

  3. Alkylation

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

Hydroformylation is the name of the reaction in which an organometallic compound inserts a hydrogen molecule into a carbon-carbon bond.

Multiple choice

What is the name of the reaction in which an organometallic compound inserts an alkyl group into a carbon-carbon bond?

  1. Carbonylation

  2. Hydroformylation

  3. Alkylation

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

Alkylation is the name of the reaction in which an organometallic compound inserts an alkyl group into a carbon-carbon bond.

Multiple choice

What is the name of the reaction in which an organometallic compound inserts an acyl group into a carbon-carbon bond?

  1. Carbonylation

  2. Hydroformylation

  3. Alkylation

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

Acylation is the name of the reaction in which an organometallic compound inserts an acyl group into a carbon-carbon bond.

Multiple choice

What are the main types of chemical reactions?

  1. Combination reactions

  2. Decomposition reactions

  3. Single-replacement reactions

  4. Double-replacement reactions

  5. Combustion reactions
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

The main types of chemical reactions are combination reactions, decomposition reactions, single-replacement reactions, double-replacement reactions, and combustion reactions.

Multiple choice

What is the chemical equation for the combustion of methane?

  1. $$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$$
  2. $$CH_4 + O_2 \rightarrow CO + 2H_2$$
  3. $$CH_4 + 2H_2O \rightarrow CO_2 + 4H_2$$
  4. $$CH_4 + 2Cl_2 \rightarrow CCl_4 + 4HCl$$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The chemical equation for the combustion of methane is $$CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O$$. This reaction is a combination reaction in which methane and oxygen react to form carbon dioxide and water.