4-Hydroxy-2-methylpentanoic acid

1-Hydroxy-4-methylpentanoic acid

1-Methyl-3-hydroxypentanoic acid

MCQ Questions for Class 11 Medical Chemistry Organic Chemistry Some Basic Principles And Techniques Quiz 3

Which of the following is/ are incorrect IUPAC name?

IUPAC name of the compound

$CH_2=CH - \underset{CH_2CH_3}{\underset{|}{C}H \,\,-}\, \underset{Cl}{\underset{|}{C}} =CH_2$

0%
3-Ethyl-4-chloropenta-1, 4-diene
0%
2-Chloro-3-ethylpenta-1, 4-diene
0%
4-Chloroethenylpent-1-ene
0%
3-Ethenyl-4-chloropent-4-ene

Explanation

$\overset{5}{C}H_2=\overset{4}{C}H - \underset{CH_2CH_3}{\underset{|}{\overset{3}{C}}H \,\,-} \,\, \underset{Cl}{\underset{|}{\overset{2}{C}}} =\overset{1}{C}H_2$

The correct IUPAC name is 2-Chloro- 3 ethyl-penta 1,4 -diene

Option B is correct.

Which of the following is gem-dihalide :

Explanation

Gem dihalides have halogens attached to the same carbon atom. For e.g.-

$CH_3-C(Cl_2)-CH_3$

The first system developed for naming of organic compounds was called Geneva system.

0%
True
0%
False

Which of the following compounds has

$-OH$ as a functional group?

0%
Butanone
0%
Butanol
0%
Butanoic acid
0%
Butanal

Explanation

In Butanone, the functional group is

$-C=O$ .
In Butanoic acid, the functional group is

$-COOH$ .
In Butanal, the functional group is

$-CHO$ .
In Butanol, the functional group is

$-OH$ .

The functional groups present in the following compound is:

$CH_{3} CH_{2} CH_{2} CH_{2} CHO$

0%
alcohol
0%
ketone
0%
carboxylate
0%
aldehyde

Explanation

The functional group present in the compound;

$CH_{3}-CH_{2}-CH_{2}-CH_{2}-CHO$ is an aldehyde group,

$-CHO.$

The functional groups present in the following compound is:

$CH_{3} CH_{2} CH_{2} COOH$

0%
carboxylic acid
0%
carbonate
0%
alcohol
0%
carboxylate

Explanation

The functional group present in

$CH_{3}-CH_{2}-CH_{2}-COOH$ is carboxylic acid,

$-COOH$ .

Which one is not a source of carbohydrate?

0%
Rice
0%
Millets
0%
Sorghum
0%
Gram

The functional group present in

$CH_{3}COOC_{2}H_{5}$ is :

0%
ketonic
0%
aldehydic
0%
ester
0%
carboxylic

Explanation

The compound with the general formula

$R-COO{R}'$ is called ester.

It's functional group is

$-COO-$ .

Option C is correct.

Which of the following is incorrectly matched?

0%
Vinegar $\rightarrow$ Carboxylic Acid
0%
$C_{2}H_{6} \rightarrow$ Alkane
0%
Ethanol $\rightarrow$ Alcohol
0%
Methanol $\rightarrow$ Ketone

Explanation

(A) Vinegar is acetic acid belongs to carboxylic acid and has a functional group

$-COOH$ .

(B)

$C_2H_6$ is belongs to the family of alkane as it has follows general formula

$C_nH_{2n+2}$ .

$-OH$ .

(D) But Methanol belongs to alcohol family not in the ketone family. It has a functional group

$-OH$ .

Hence, option D is incorrectly matched.

The functional groups present in the following compound is:

$CH_{3} CH_{2} OH$

0%
ketone
0%
alcohol
0%
aldehyde
0%
carboxylate

Explanation

The functional group in

$CH_{3}-CH_{2}-OH$ is an alcoholic group,

$-OH$ .

Which of the following is/are functional groups?

0%
Hydroxyl group
0%
Aldehyde group
0%
Carboxylic group
0%
All of the above

Which of the following are trivial name of organic compounds?

0%
vinegar
0%
furyl aldehyde
0%
acetic acid
0%
acrolein

Explanation

Vinegar is the trivial name of the aqueous solution of acetic acid (

$CH_{3}COOH$ ).
Acrolein is the trivial name of 2-propenal (

$CH_{2}= CH-CHO$ ).

Identify divalent functional group:

0%
esters
0%
ketones
0%
aldehydes
0%
alcohol

Methyl group is:

0%
$- CH_{2}$
0%
$- CH_{2}OH$
0%
$- CH_{2}Cl$
0%
$- CH_{3}$

Explanation

$-CH_3$ group is called methyl group, not

$-CH_2$ .

Which of these contains the carbonyl group?

0%
ketones
0%
aldehydes
0%
carboxylic Acids
0%
all of these

Explanation

Carbonyl group is

$-C=O$ , which is present in ketones, aldehydes and carboxylic acids, etc. having a functional group

$-C=O$ ,

$-CHO$ and

$-COOH$ respectively.

Compound

$CH_3CH_2CH(CH_3)CH_2COCl$ has the IUPAC name_______.

0%
3-methylpentanoyl chloride
0%
1-chloroformyl-2-methylbutane
0%
1 -cloroformyl-1-secbutylmethane
0%
none of the above

Explanation

IUPAC Name of this compound is;

$C\overset {5}{H_{3}}\overset {4}{CH_{2}} \underset {\underset {CH_{3}}{|}}{\overset {2}{CH}} \overset {2}{CH_{3}} \overset {1}{CO}Cl$

$A)\rightarrow 3- methyl\ pentanoyl\ chloride$ .

The correct IUPAC name of

$CH_{3} C H_{2} CH_{2} CH_{3}$ is n-butane not butane.

0%
True
0%
False

Explanation

The prefix n- is not part of IUPAC system. Hence the correct name for

${ CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }{ CH }_{ 3 }$ is butane, n-butane is its common name, although nowadays, it too is also, acceptable to IUPAC system.

IUPAC name of compound

$C_{4}H_{9}SH$ is______.

0%
butanol
0%
butanethiol
0%
butanesol
0%
butanol sulphur

Which of the following statements about IUPAC system of nomenclature is /are correct?

0%
This system of nomenclature was introduced in 1947.
0%
On the basis of this system, the name of an organic compound consists of word root, suffix, and prefix.
0%
This system was first introduced in 1892.
0%
The latest IUPAC system is based on recommendation made in 1993.

The general formula

$C_{n}H_{2n}O_{2}$ could be for open chain:

0%
diketones
0%
carboxylic acids
0%
diols
0%
dialdehydes

Explanation

The general formula

$C_{n}H_{2n}O_{2}$ could be for open chain carboxylic acids. Thus, butanoic acid

$\displaystyle CH_3-CH_2-CH_2-COOH$ has formula

$\displaystyle C_4H_8O_2$ . And, decanoic acid

$\displaystyle CH_3-(CH_2)_8-COOH$ has formula

$\displaystyle C_{10}H_{20}O_2$

$CCl_3 - CHO$ in IUPAC system is called:

0%
chloral
0%
1, 1, 1-trichloroethanal
0%
2, 2, 2-trichloroethanal
0%
Trichloroacetaldehyde

Explanation

IUPAC name of

$Cl_{3}C-CHO$ is 2,2,2-trichloroethanal, as the functional group is aldehyde and is cited first than the three chloro groups .

Among the following compounds, the most acidic is:

0%
p-nitrophenol
0%
p-hydroxybenzoic acid
0%
o-hydroxybenzoic acid
0%
none

Explanation

Hint: According to the Bronsted-Lowry concept, an acid is a molecule or ion capable of donating a proton $H^+$ .

Correct Answer: Option C

Explanation:

A mono-substituted benzoic acid is a stronger acid than a mono-substituted phenol due to the presence of a carboxylic acid group.
Among the given substituted benzoic acid, ortho-hydroxy benzoic acid is the strongest acid.
The high stabilization of the conjugate base is due to the presence of intra- molecular H-bonding between $O^-$ of $COO^-$ and $H$ of $OH$ .

Hence, $o-hydroxybenzoic$ $acid$ is the strongest acid.

The IUPAC name is :

0%
1-Hydroxy-4-methylpentanoic acid
0%
1-Methyl-3-hydroxypentanoic acid
0%
4-Hydroxy-2-methylpentanoic acid
0%
4-Carboxypentanol-2

Which of the following compound is wrongly named ?

0%
0%
0%
$CH_3CH_2CH_2-CH(CH_3)(CH_3)$ 2-Methylpentane
0%
$CH_3-CH(CH_3)-CH_2-CH_2-CHO$ 2-Methyl, 1-pentanal

The IUPAC name of the compound is:

0%
3,3-dimethyl-1-hydroxy cyclohexane
0%
1,1-dimethyl-3-hydroxy cyclohexane
0%
3,3-dimethyl-1-cyclohexanol
0%
none of the above

Explanation

The IUPAC name of the compound should be

(Numbering starts from

$OH$ in an anticlockwise direction)

The name would be,

3,3-dimethyl1-1-cyclohexanol.

Hence, the correct option is

$\text{C}$

1073584_128581_ans_430e9b2186b64a68842bf9ba60794e2b.png

IUPAC name of the compound ?

0%
hexanoic acid 5 - al - 1
0%
6-oxohexanoic acid
0%
hexanal-1-carboxylic acid
0%
none of these

Explanation

Following steps are followed while naming the compound;

$CHO-(CH_{2})_{6}COOH$ :
i) The parent chain consists of 8 carbon atoms and the primary functional group is;

$-COOH$ , thus the suffix -oic acid is used.
ii)

$-CO$ is the secondary functional group and the prefix -oxo is used for it.
iii) The numbering of the compound is done from right to left as the lowest number is given to the primary functional group;

$-COOH$ .
Thus the name of the compound is; 6-oxohexanoic acid.

The number of sigma and pi bonds in benzene are:

0%
$6\sigma$ and $3\pi$
0%
$12\sigma$ and $3\pi$
0%
$9\sigma$ and $3\pi$
0%
$6\sigma$ and $6\pi$

The IUPAC name of the compound shown above is:

0%
1,1-diethyl-2-dimethylpentane
0%
4,4-dimethyl-5,5-diethylpentane
0%
5,5-diethyl-4,4-dimethylpentane
0%
3-ethyl-4,4 dimethylheptane

Explanation

Hint:-

$\textbf{Use IUPAC Nomenclature to name this compound.}$

$\textbf{Step 1: Selecting and numbering the parent chain}$

$\text{Rules used for selecting and numbering the parent chain.}$

$\bullet$ It should be longest chain.

$\bullet$ Numbering should start from the terminal carbon.

$\bullet$ Numbering should be done in such a way that the first substituent should be on the lowest number of the parent chain.

Now using the above rule we can number the chains like this.

$\textbf{Step 2: Name the compund.}$

At position 3 we have ethane and at 4 we have 2 methane and our longest chain has 7 carbon atoms.

Also,

$\bullet$ There should be "-" between number and name.

$\bullet$ There should be "," between two numbers.

So the name is 3-ethyl-4,4-dimethylheptane

$\textbf{Hence the correct option is D}$

Which of the following is crotonic acid?

0%
$\displaystyle CH_{2}=CH-COOH$
0%
$\displaystyle C_{6}H_{5}-CH=CH-COOH$
0%
$\displaystyle CH_{3}-CH=CH-COOH$
0%
$\displaystyle C_{6}H_{5}-COOH$

Explanation

The structure of crotonic acid is

$\displaystyle CH_{3}-CH=CH-COOH$ . It is an unsaturated acid.

So, the correct option is

$C$

The IUPAC name of the above compound is:

0%
3-pentanol
0%
3-pentanal
0%
3-pentanoic acid
0%
3-pentane

Explanation

1 2 3 4 5

$CH_3 -CH_2-CH-CH_2-CH_3$

$\begin{array}{l}\text { There are } 5 \text { carbon atoms in main chain and } 3 \mathrm{rd} \\\text { carbon has alcoholic functional group. } \\\text { Hence IUPAC name is } 3 \text { -pentanol }\end{array}$

The correct IUPAC name of is:

0%
2-methylenebutanoic acid
0%
2-ethylprop-2-enoic acid
0%
2-carboxybutene
0%
None of the above

IUPAC name of this compound is:

0%
ethyl-4-methyl-3-oxopentanoate
0%
2-ethoxycarbonylpentan-3-one
0%
4-ethoxycarbonylpentan-3-one
0%
ethyl-2-methyl-3-oxopentanoate

Which among the following is/are natural source(s) of organic compounds ?

0%
coal
0%
natural gas
0%
petroleum
0%
all of the above

Formula of acetic acid is :

0%
$HCOOH$
0%
$CH_3CH_2COOH$
0%
$CH_3COOH$
0%
$C_3H_7COOH$

Explanation

Ethanoic acid or acetic acid is a colourless liquid. It's chemical formula is

$C_{2}H_{4}O_{2}$ or

$CH_{3}COOH$

The functional group present in acetic acid is:

0%
$-C = O$
0%
$- OH$
0%
$- CHO$
0%
$-COOH$

An organic compound whose functional group is carboxyl is :

0%
ethyne
0%
ethanol
0%
acetic acid
0%
ethanone

Explanation

Acetic acid:

$CH_3COOH$

The nodal plane in the

$\pi$ -bond of ethene is located in:

0%
the molecular plane
0%
a plane parallel to the molecular plane
0%
a plane perpendicular to the molecular plane which bisects the carbon-carbon $\sigma$ -bond at right angle
0%
a plane perpendicular to the molecular plane which contains the carbon-carbon $\sigma$ -bond

Explanation

The nodal plane in the $\pi$ -bond of ethene is located in the molecular plane. A $\pi$ -bond has a nodal plane passing through the two bonded nuclei, i.e., molecular plane.

In ethene, there are five sigma bonds in one plane: one $C-C$ sigma bond and four $C-H$ sigma bonds.The $\pi$ - bond is formed perpendicular to the plane in which one lobe of electron density is above the plane and one lobe of electron density is below the plane.The nodal plane of the $\pi$ - bond is in between the two lobes of electron density of the $\pi$ - bond.

State whether the given statement is true or false.

Statement: The IUPAC name of the compound is ethanol.

0%
True
0%
False

Explanation

$\begin{array}{l}\text { The functional group present in the compound is } \\\text { Carboxyllic Acid. } \\\text { Hence IUPAC name is Ethanoicacid } \\\text { Therefore given statement is False. }\end{array}$
1990395_193607_ans_e919a277ed7348679bacf664c9359df5.PNG

1990395_193607_ans_e919a277ed7348679bacf664c9359df5.PNG

${ CH_3} -{ \underset { | } CH} -{ CH_3}$

$CH_3$

The IUPAC name of the compound is:

0%
1-methyl propane
0%
2-methyl propane
0%
butane
0%
2-methyl butane

Which of the following statements is/are correct?

0%
The trivial names of organic compounds are called common names.
0%
The systematic names of organic compounds are obtained from the IUPAC system.
0%
The systematic names of alkanes are based on the number of C atoms in the longest continuous chain of C atoms.
0%
The maximum number of functional groups must be included in the C atom chain selected even if it does not satisfy the longest chain rule.

Which of the following statements is/are not correct?

0%
$\pi$ - bond always exists with sigma -bond according to Valence Bond Theory
0%
$\pi$ - bond can exist independently according to Valence Bond Theory
0%
$\sigma$ - bond is weaker than pi-bond
0%
$\pi$ - bond is less reactive than sigma-bond

Explanation

(A)

$\pi-$ bond always exists with sigma-bond according to Valence Bond Theory.

(B)

$\pi-$ bond cannot exist independently.

$\pi$ bond are usually weaker than sigma bonds. Quantum mechanics says this is because the orbital paths are parallel so there is much less overlap between the p-orbitals.

$\pi$ bonds happen when two atomic orbitals are in contact through two areas of overlap.

(D) Unsaturated compounds (containing pi bonds due to the existence of a double bond) are more reactive than saturated compounds (containing only sigma bonds) because the electron density at the internuclear axis is zero in a

$\pi$ bond ( in contrast to the sigma bond).

$\pi$ bonds involve sideways overlap while sigma bond involves a head-on or axial overlap.

$\pi$ -Bonding occurs in each of the following except :

0%
$CO_{2}$
0%
$C_{2}H_{4}$
0%
$CN^{-}$
0%
$CH_{4}$

Explanation

$\pi$ -Bonding occurs in

$CO_{2}$ ,

$C_{2}H_{4}$ and

$CN^{-}$ .
However, it does not occur in

$CH_{4}$ as it is a saturated molecule having all the four sigma bonds.

0%
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
0%
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
0%
Assertion is correct but Reason is incorrect.
0%
Both Assertion and Reason are incorrect.

Explanation

Functional groups are groups of atoms that occur within organic molecules and confer specific chemical properties to those molecules. When functional groups are shown, the organic molecule is sometimes denoted as

$"R"$ . Functional groups are found along the “carbon backbone” of macromolecules which is formed by chains and/or rings of carbon atoms with the occasional substitution of an element such as nitrogen or oxygen. Molecules with other elements in their carbon backbone are substituted hydrocarbons. Each of the four types of macromolecules—proteins, lipids, carbohydrates, and nucleic acids—has its own characteristic set of functional groups that contributes greatly to its differing chemical properties and its function in living organisms.

How would you name the following compound?

$_3$ -CH

$_2$ -Br

0%
Bromo ethane
0%
Bromo pentane
0%
Bromo hexane
0%
None of these

Explanation

Bromoethane, also known as ethyl bromide, is a chemical compound of the haloalkanes group.

$H_2C=CH_2$ + HBr

$\rightarrow$

$H_3C-CH_2Br$
Option A is correct.

Which of the following is zerone?

0%
$CH_3CHO$
0%
$CH_3OH$
0%
$CH_4$
0%

$C_2H_5OH$

$2-chloro-3-methyl\ hexanoic acid$ , the primary suffix is:

0%
$2-chloro-$
0%
$-3-methyl$
0%
$an(e)$
0%
$oic\ acid$

Butanone is a four-carbon compound. The functional group present is:

0%
carboxylic acid
0%
aldehyde
0%
ketone
0%
alcohol

Butanone is a four-carbon compound with the functional group :

0%
carboxylic acid
0%
aldehyde
0%
ketone
0%
alcohol

Explanation

Explanation:

Butanone has total $4$ carbons present in it.
The structure of butanone is shown as;

As the name suggest, butanone so $buta-$ means $4 \ C$ and $-one$ is the prefix for $\bf{ketone}$ functionality.

Final answer: The correct answer is $C$

The fusion of an organic compound with solid sodium hydroxide is undertaken for testing nitrogen, sulphur and halogens. This test is called:

0%
Dumas method
0%
Carius method
0%
Kjeldahl's method
0%
Lassaigne's test

Explanation

It is a general test for the detection of halogens, nitrogen and sulphur in an organic compound. These elements are covalently bonded to the organic compounds. In order to detect them, these have to be converted into their ionic forms (

$e.g\: CN^−, S^{−2}, PO_3^{−4}$ and

$X^−$ ions). This is done by fusing the organic compound with sodium metal. The ionic compounds formed during the fusion are extracted in aqueous solution and can be detected by simple chemical tests. This is called Lassaigne's test.

CBSE Questions for Class 11 Medical Chemistry Organic Chemistry Some Basic Principles And Techniques Quiz 3 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry Organic Chemistry Some Basic Principles And Techniques Quiz 3 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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