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 planet earth acid deposition air and air pollution natural resources- air, water and land

Which of the following reactions is not correct for the formation of acid rain?

  1. $\displaystyle { N } _{ 2 }+{ O } _{ 2 }\rightarrow 2NO$
  2. $\displaystyle 2NO+{ O } _{ 2 }\rightarrow { 2NO } _{ 2 }$
  3. $\displaystyle { H } _{ 2 }O+2{ NO } _{ 2 }\rightarrow { HNO } _{ 2 }+{ HNO } _{ 3 }$
  4. $\displaystyle NO+{ O } _{ 2 }\rightarrow { NO } _{ 2 }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$\displaystyle NO+{ O } _{ 2 }\rightarrow { NO } _{ 2 }$ is the incorrect equation as it is not balanced. 

Multiple choice chemistry planet earth acid deposition air and air pollution natural resources- air, water and land

Which of the following reactions is taking place resulting in discolouration of marble of the buildings like Taj Mahal?

  1. $CaC{ O } _{ 3 }+{ H } _{ 2 }S{ O } _{ 4 }\longrightarrow CaS{ O } _{ 4 }+{ H } _{ 2 }O+C{ O } _{ 2 }$
  2. $CaC{ O } _{ 3 }+{ H }Cl\longrightarrow CaC{ l } _{ 2 }+{ H } _{ 2 }O+C{ O } _{ 2 }$
  3. $CaC{ O } _{ 3 }+{ H } _{ 2 }O\longrightarrow Ca{ \left( OH \right) } _{ 2 }+C{ O } _{ 2 }$
  4. $CaC{ O } _{ 3 }\longrightarrow CaO+C{ O } _{ 2 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Acid rain is the state when the pH of rain falls below 5.6.  Acid rain damages the buildings and statues as they dissolve and corrodes the heavy metals. This happens when sulphuric acid nitric acids in the polluted air react with calcite in marble, the calcite dissolves. It also dissolves metals from soils, rocks and sediments.  

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

$SO _3 + Mg(OH) _2 \rightarrow $

  1. no reaction
  2. $Mg(OH) _2$
  3. $Mg(SO _4)$
  4. $H _2O$
Reveal answer Fill a bubble to check yourself
C,D Correct answer
Explanation

$SO _3$ is a non-metallic oxide which is acidic in nature and reacts with base to give a general neutralization reaction by forming a salt and water as


$SO _3+Mg(OH) _2\rightarrow MgSO _4+H _2O$
                                            Salt        water
Correct option - C,D

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

Identify $A$ and $B$ in the following reaction.
$  A + B  \rightarrow  MgCl _2(aq) + 2H _2O(l) $

  1. $Mg(OH) _2$(s) + $2H _2SO _4(aq)$
  2. $Mg(OH) _2(s)$ + $2HCl(aq)$
  3. $MgOH(s)$ + $2HCl(aq)$

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Acid gets neutralized when it reacts with a metal oxide to give salt and water. 
Magnesium hydroxide + hydrochloric acid $\rightarrow$ magnesium chloride + water
$ Mg(OH) _2(s) + 2HCl(aq) \rightarrow MgCl _2(aq) + 2H _2O(l) $

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

? $ \rightarrow BaSO _4(aq) + H _2O(l) $
What are the reactants used to carry out this reaction?

  1. $SO _4(g) + Ba(OH) _2$
  2. $SO _3(g) + Ba(OH) _2$
  3. $SO _3(g) + BaOH$

  4. The reaction does not occur.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The non-metal oxides can be neutralized with a base to form a salt and water.
$ SO _3(g) + Ba(OH) _2(aq) \rightarrow BaSO _4(aq) + H _2O(l) $

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

Which of the following represents the products obtained when ferrous oxide reacts with nitric acid?

  1. Ferric nitrate, $NO$ and water
  2. Ferrous nitrate, $NO$ and water
  3. Ferric nitrate, $NO _2$ and water
  4. Ferrous nitrate, $NO _2$ and water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When ferrous oxide reacts with nitric acid, the products obtained are ferric nitrate, $NO$ and water.
$3FeO + 10HNO _3 \rightarrow 3Fe(NO _3) _3 + NO + 5H _2O$

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

Which of the following represents the products obtained when $CuO$ reacts with nitric acid?

  1. $CuNO _3$ and water
  2. $CuNO _3$ and hydrogen
  3. $Cu(NO _3) _2$ and hydrogen
  4. $Cu(NO _3) _2$ and water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Wen $CuO$ reacts with nitric acid, $CuNO _3$ and water are obtained.
$CuO + 2HNO _3 \rightarrow Cu(NO _3) _2 + H _2O$

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

Which of the following represents the products of the reaction between $NaOH $ and sulphur dioxide?

  1. $NaHSO _3$
  2. $Na _2SO _3$
  3. Both $ A$ and $B$

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The products of the reaction between $NaOH$ and sulphur dioxide are either $NaHSO _3$ or $Na _2SO _3$
$SO _2 + NaOH \rightarrow NaHSO _3$
$SO _2 + 2NaOH \rightarrow  Na _2SO _3 + H _2O$

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

When NaOH reacts with $NO _2$, the products obtained are $NaNO _2$ and $NaNO _3$
$2NaOH + 2NO _2 \rightarrow NaNO _2 + NaNO _3 + H _2O$
From this reaction, which nature of $NO _2$ can we conclude?

  1. Acidic

  2. Basic

  3. Amphoteric

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

We can conclude that $NO _2$ is acidic in nature as it reacts with a base $(NaOH)$ to form salt and water.

Multiple choice chemistry chemistry in everyday life metal oxides and non metal oxides reactions of acids and bases properties of acids and bases

The reaction between dinitrogen trioxide and potassium hydroxide gives $KNO _2$.
$N _2O _3 + 2KOH  \rightarrow 2KNO _2 + H _2O$


What can we conclude about the nature of dinitrogen trioxide?

  1. It is acidic oxide

  2. It is basic oxide

  3. It is amphoteric oxide

  4. It is neutral oxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
$N _2O _3 + 2KOH  \rightarrow 2KNO _2 + H _2O$

In the above reaction, we can see that dinitrogen trioxide is an acidic oxide, as $N _2O _3$ reacts with a base $(KOH)$ to form salt and water. This is the characteristic of acidic oxide.
Hence, option $A$ is correct.