MCQ 11 Mark
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 $(A)\ :$ Esterification is a process in which a sweet smelling substance is produced.
Reason $(R)\ :$ When esters react with sodium hydroxide an alcohol and sodium salt of carboxylic acid are obtained.
- 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.
When alcohol is added to carboxylic acid with sodium hydroxide and heated in bath tub, it produces a sweet smell of ester and this process is called Esterification.
View full question & answer→MCQ 21 Mark
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 $(A):$ In a homologous series of alcohols, the formula for the second member is $C _2 H _5 OH$ and the third member is $C _3 H _7 OH$.
Reason$(R):$ The difference between the molecular masses of the two consecutive members of a homologous series is $144 .$
- 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.
A homologous series is a series of organic compounds that contains identical functional group and differs only in the length of the carbon chain in the compound.
The general formula for homologous series for alcohols is $C ( n ) H (2 n +1) OH$, where $n$ is a natural number.
Substituting $n=2$ and $n=3$ we get $C _2 H _5 OH$ and $C _3 H _7 OH$ respectively, which verifies the assertion made.
The two consecutive members of the homologous series varies only by a $CH _2$ group, hence the difference in molecular mass of two consecutive members is equal to $14 .$
View full question & answer→MCQ 31 Mark
The following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion Alcohol cannot be used as an additive in petrol.
Reason Alcohol give rise to $CO$ and $H_2O$ when burnt in sufficient air.
- 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.
- C
If Assertion is true, but Reason is false.
- ✓
If Assertion is false, but Reason is true.
AnswerCorrect option: D. If Assertion is false, but Reason is true.
In the absence of subsidy, there would be very little use of ethanol as a fuel. But those are no the only reasons. Ethanol carries less energy than the same volume of gasoline. Ethanol is also much more hygroscopic than gasoline, absorbing significant amounts of water from air.
View full question & answer→MCQ 41 Mark
For question 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 : Carbon and its compounds can be used as fuels.
Reason : They are highly inflammable and have high calorific value.
- ✓
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
For question 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 : Diamond is the hardest natural known substance.
Reason : Diamond is used for cutting marble, granite and glass.
- 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 61 Mark
The following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
Assertion Diamond does not conduct electricity.
Reason Diamond has high refractive index.
- 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.
If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion. A material’s ability to conduct electricity is determined by the number and mobility of its free electrons.
In diamond, each carbon atom uses all four of its valence electrons to bond with neighboring atoms. That doesn’t leave any electrons free for conducting electricity.
View full question & answer→MCQ 71 Mark
For question 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 : Graphite is soft and slippery to touch.
Reason : Graphite has sheet like layered structure.
- ✓
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 81 Mark
For question 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 : Both aldehydes and ketones contain carbonyl group.
Reason : In aldehydes, the functional group is attached to atleast one hydrogen atom.
- 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 91 Mark
For question 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 : Saturated hydrocarbons are chemically less reactive.
Reason : All the valencies of carbon atom are satisfied by single covalent bonds.
- ✓
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 101 Mark
For question 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 : Carbon possesses property of catenation.
Reason : Carbon atoms form double as well as triple bonds during catenation.
- 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.
Catenation property of carbon is primarily due to its small size, electronic configuration and unique strength of carbon $-$ carbon bonds.
View full question & answer→MCQ 111 Mark
For question 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: Diamond and graphite do not have the same crystal structure.
Reason: Diamond is crystalline while graphite is amorphous.
- 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.
In diamond, $C-$atoms are $sp^3$ hybridized while in graphite, they are $sp^2$ hybridized. Diamond and graphite both are crystalline forms of carbon.
View full question & answer→MCQ 121 Mark
For question 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 : Graphite is a good conductor of electricity.
Reason : lt has one free valence electron.
- ✓
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.
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