MCQ 11 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)} $ and $(d)$ as given below :
Assertion : ln a balanced chemical equation, total mass of the reactants is equal to the total mass of the products.
Reason : Mass can neither be created nor destroyed during a chemical change.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
This is according to the law of conservation of mass.
View full question & answer→MCQ 21 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: $\ce{MnO_2 + 4HCl → MnCl_2 + Cl_2 + 2H_2O,}$ is a redox reaction.
Reason: $\ce{MnO_2}$ oxidises $\ce{HCl}$ to $\ce{Cl_2}$ and gets reduced to $\ce{MnCl_2}$.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 31 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below:
Assertion : Exposure of silver chloride to sunlight for a long duration turns gray due to the formation of silver by decomposition of silver chloride.
Reason : ln this process, sublimation of silver chloride takes place.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
View full question & answer→MCQ 41 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The food items containing oil and fat are flushed with nitrogen.
Reason : Oil and fat become rancid on oxidation which has the bad taste and smell.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 51 Mark
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion : $2\text{Na}+\text{H}_2\rightarrow2\text{NaH}$
In the above chemical equal, sodium is getting oxidised and $H_2$ is getting reduced.
Reason : The chemical reaction in which oxidation and reduction take place simultaneously, are called redox reactions.
- A
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- ✓
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- C
If Assertion is true, but Reason is false.
- D
If Assertion is false, but Reason is true.
AnswerCorrect option: B. If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
$2\text{Na}+\text{H}_2\rightarrow2\text{NaH}$
In the above chemical equal, sodium is getting oxidised and $H_2$ is getting reduced.
View full question & answer→MCQ 61 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The reaction during which hydrogen is lost is called oxidation reaction.
Reason : Reducing agent removes hydrogen from another substance.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
Reducing agent gives hydrogen to another substance.
View full question & answer→MCQ 71 Mark
For two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: A lead nitrate on thermal decomposition gives lead oxide, brown coloured nitrogen dioxide and oxygen gas.
Reason: Lead nitrate reacts with potassium iodide to form yellow ppt. of lead iodide and the reaction is double displacement as well as precipitation reaction.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion
Decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances.
$\ce{2Pb(NO_3)_2 \rightarrow 2Pb0 + 4NO_2 + O_2}$
View full question & answer→MCQ 81 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Magnesium ribbon keeps on burning in atmosphere of nitrogen.
Reason : Magnesium reacts with nitrogen to form magnesium nitride and this reaction is combination reaction.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 91 Mark
For two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Following reaction describes the rusting of iron and is a redox reaction.
$\ce{4Fe + 3O_2 \rightarrow 4Fe^{3+} + 60^{2-}.}$
Reason: The metallic iron is oxidised to $Fe^{3+}.$
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Fe is oxidised to $Fe^{3+}$ and acts as reducing.
View full question & answer→MCQ 101 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Corrosion of iron is Connolly known as rusting.
Reason : Corrosion of iron occurs in presence of moist air.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 111 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Iron articles are painted so as to prevent them from rusting.
Reason : When the surface of iron is coated with paint, its surface does not come in contact with oxygen and moisture therefore rusting does not take place.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 121 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: $\ce{2H_2S(g) + O_{2(g)} → 2S_{(g)} + 2H_2O_{(l)} }$lt is a redox reaction.
Reason: ln redox reaction, oxidation and reduction take place simultaneously.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 131 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: $AgBr$ is used on photographic and $X-$ray film.
Reason: $AgBr$ is photosensitive and changes to $Ag$ and bromine in presence of sunlight and undergoes decomposition reaction.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
$\ce{AgBr}$ is a chemical compound. It is widely used in photography as photographic emulsions.
$\ce{2AgBr \rightarrow 2Ag + Br_2}$
View full question & answer→MCQ 141 Mark
For two statements are given$-$one labelled Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.
Reason: The decomposition reaction takes place on application of heat, therefore, it is an endothermic reaction.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
$\ce{CaCO_3}$ on heating gives $\ce{CO_2}$ and $\ce{CaO.}$
View full question & answer→MCQ 151 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Food materials are often packed in air tight container.
Reason : Oxidation, resulting in rancidity, is prevented.
- ✓
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: A. Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
View full question & answer→MCQ 161 Mark
In the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion : The following chemical equation is an example of thermal decomposition reaction.$2\text{KClO}_3(\text{s})\xrightarrow[\text{Catalyst}]{\text{Heat}}2\text{KCl}(\text{s})+3\text{O}_2(\text{g})$
Reason : Heat gets released in the decomposition reactions.
- A
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
- B
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
- ✓
If Assertion is true, but Reason is false.
- D
If Assertion is false, but Reason is true.
AnswerCorrect option: C. If Assertion is true, but Reason is false.
$2\text{KClO}_3(\text{s})\xrightarrow[\text{Catalyst}]{\text{Heat}}2\text{KCl}(\text{s})+3\text{O}_2(\text{g})$
It is a decomposition reaction and endothermic in nature :
In a decomposition reaction, a compound is broken down into two or more simpler substances. This reaction is a decomposition reaction as $\ce{KClO}_3$ is broken down into $\ce{KCl}$ and $O _2$. It is also endothermic reaction because during decomposition of $\ce{KClO}_3$ heat is taken in for the formation of desired products.
View full question & answer→MCQ 171 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Zinc reacts with sulphuric acid to form zinc sulphate and hydrogen gas and it is a displacement reaction.
Reason : Zinc reacts with oxygen to form zinc oxide.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 181 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Rusting of iron metal is the most common form of corrosion.
Reason : The effect of rusting of iron can be reversed if they are left open in sunlight.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
View full question & answer→MCQ 191 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Chips manufacturers usually flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.
Reason : This increase the taste of the chips and helps in their digestion.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- ✓
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: C. $A$ is true, but $R$ is false.
This is because nitrogen is an antioxidant. It prevents the chips from being oxidised.
View full question & answer→MCQ 201 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: ln the reaction, $\text{Zn}_\text{(s)}+ 2\text{H}^+_{\text{(aq)}}\rightarrow\text{Zn}^{2+}_{\text{(aq)}} + \text{H}_{2_\text{(g)}}$ zinc acts as an oxidising agent and $H^+$ acts as a reducing agent.
Reason: An oxidising agent accepts electrons while a reducing agent loses electrons.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- B
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- ✓
$A$ is false, but $R$ is true.
AnswerCorrect option: D. $A$ is false, but $R$ is true.
$\text{Zn}_\text{(s)}+ 2\text{H}^+_{\text{(aq)}}\rightarrow\text{Zn}^{2+}_{\text{(aq)}} + \text{H}_{2_\text{(g)}}$
ln this reaction, zinc loses electrons and so it is a reducing agent, while $H^+$ gains electrons and so it is an oxidising agent.
View full question & answer→MCQ 211 Mark
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Chemical reaction changes the physical and chemical state of a substance.
Reason : When electric current is passed through water $($liquid$),$ it decomposes to produce hydrogen and oxygen gases.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→MCQ 221 Mark
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Magnesium wire bums in presence of $O_2.$
Reason: Magnesium acts as a reducing agent.
- A
Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
- ✓
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
- C
$A$ is true, but $R$ is false.
- D
$A$ is false, but $R$ is true.
AnswerCorrect option: B. Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
View full question & answer→