Carbon And Its Compounds(10th Grade > Chemistry ) Questions and answers for exam Preparation

10th Grade > Chemistry

CARBON AND ITS COMPOUNDS MCQs

Total Questions : 56 | Page 4 of 6 pages

Question 31.

The functional group in butan-1-ol is:

-OH
-COOH
-CHO
-NH₂

Discuss Question

Answer: Option A. -> -OH
:
A

The IUPAC name of the given molecule, has '-ol' as its suffix.
'-ol' is the suffix for alcohols. Hence, the functional group of an alcohol is -OH.

Question 32.

Detergents are ammonium or sulphonate salts of long chain _________.

Aldehydes
Ketones
Carboxylic acids
Alcohols

Discuss Question

Answer: Option C. -> Carboxylic acids
:
C

Detergents are ammonium or sulphonate salts of long chain carboxylic acids. So the resulting compound is called sulphonic acid. Sulphonic acids are used in making detergents while carboxylic acids (fatty acids) are used in soap making processes.

Question 33.

The molecular formula of the given compound is ________.

$C_{6} H_{6}$
$C_{6} H_{12}$
$C_{6} H_{18}$
$C_{6} H_{9}$

Discuss Question

Answer: Option B. ->

C_{6} H_{12}

:
B
In line structure representation of carbon compounds, each line represents a C-C bond and the remaining valencies are satisfied by hydrogen atoms.
The expanded structure is given below.

The Molecular Formula Of The Given Compound Is ________.

The compound is called cyclohexane. Its molecular formula is

C_{6} H_{12}

Question 34.

The combination of which of the following compounds will give an ester?

Methanone and propanal
Methanal and propanol
Methanol and propanoic acid
Methanone and formic acid

Discuss Question

Answer: Option C. -> Methanol and propanoic acid
:
C

Esters are obtained from the reaction between carboxylic acid and alcohols. The reaction between methanol and propanoic acid in the presence of concentrated sulphuric acid leads to the formation of methyl propanoate, an ester.

$C H_{3} O H (a q) + C H_{3} C H_{2} C O O H (a q) \to C H_{3} C H_{2} C O O C H_{3} (a q) + H_{2} O (l)$

Question 35.

What is the name of the compound given below?

But-2-ene
But-1-yne
Butane
Butene

Discuss Question

Answer: Option C. -> Butane
:
C

∙

The compound given has four carbon atoms so the word root for this compound is 'but'.

∙

Since all the carbon atoms are bonded to each other by only single bonds, this compound is an alkane and the suffix in this case will be '-ane'.
Therefore, the name of this compound is butane.

Question 36.

Select the option that will complete the homologous series given below.
$C_{2} H_{4}$ , $C_{3} H_{6}$ , _______, $C_{5} H_{10}$ , $C_{6} H_{12}$

$C_{4} H_{6}$
$C_{4} H_{10}$
$C_{4} H_{4}$
$C_{4} H_{8}$

Discuss Question

Answer: Option D. ->

C_{4} H_{8}

:
D
The homologous series given here is the alkene series. In a homologous series, every successive member differs by

{CH}_{2}

group. So, the successive member after

C_{3} H_{6}

in the given alkene homologous series is

C_{4} H_{8}

Question 37.

Ethane, with the molecular formula $C_{2} H_{6}$ , has ____ covalent bonds.

six
seven
eight
nine

Discuss Question

Answer: Option B. -> seven
:
B
A covalent bond involves the sharing of electron pairs between two elements. Given below is the structure of ethane, having molecular formula

C_{2} H_{6}

Ethane has seven covalent bonds, i.e., six C-H bonds and one C-C bond.

Question 38.

Which amonst the following will give a pleasant smell of ester when heated with ethanol and a small quantity of sulphuric acid?

${CH}_{3} COOH$
${CH}_{3} CO {CH}_{3}$
${CH}_{3} OH$
${CH}_{3} CHO$

Discuss Question

Answer: Option A. ->

{CH}_{3} COOH

:
A
Any carboxylic acid on reaction with an alcohol in presence of concentrated sulphuric acid gives an ester.
In the given options, only

{CH}_{3} COOH

, i.e., ethanoic acid on reaction with ethanol in presence of concentrated sulphuric acid will give an ester (ethyl ethanoate).
This reaction is called esterification reaction.

{CH}_{3} COOH (aq) + {CH}_{3} {CH}_{2} OH (aq) conc . H_{2} {SO}_{4} - ----- \to {CH}_{3} {CH}_{2} {COOCH}_{3} (aq) + H_{2} O (aq)

Question 39.

The general formula for alkynes is:

$C_{n} H_{2 n + 2}$
$C_{n} H_{n}$
$C_{n} H_{2 n - 2}$
$C_{n} H_{2 n}$

Discuss Question

Answer: Option C. ->

C_{n} H_{2 n - 2}

:
C

∙

Alkynes are hydrocarbons having atleast one triple bond between its carbon atoms. The general formula for alkynes is

C_{n} H_{2 n - 2}

∙

Alkanes are hydrocarbons having only single bonds between its carbon atoms. The general formula for alkanes is

C_{n} H_{2 n + 2}

∙

Alkenes are hydrocarbons having atleast one double bond between its carbon atoms. The general formula for alkenes is

C_{n} H_{2 n}

Question 40.

Choose the correct option based on the statements given:
Statement 1: Carbon always share electrons to form a covalent bond with other elements.
Statement 2: $C^{4 +}$ and $C^{4 -}$ ions are highly unstable.

Both statements are correct but statement 2 is not the correct explanation for statement 1.
Both statements are correct and statement 2 is the correct explanation for statement 1.
Statement 1 is wrong but statement 2 is correct.
Statement 1 is correct but statement 2 is wrong.

Discuss Question

Answer: Option B. -> Both statements are correct and statement 2 is the correct explanation for statement 1.
:
B
Carbon cannot donate or accept electrons to obtain noble gas configuration as

C^{4 -}

and

C^{4 +}

are unstable in nature.

$C^{4 -}$ is unstable because it would be difficult for the nucleus with six protons to hold on to ten electrons.

$C^{4 +}$ is unstable because it would require an excessively large amount of energy to remove four electrons.

Since both $C^{4 -}$ and $C^{4 +}$ ions are unstable in nature, carbon overcomes this problem by sharing its valence electrons with other atoms to obtain the nearest noble gas electronic configuration.