Tag: chemistry

Questions Related to chemistry

Statement I: Methane is defined as a compound
Statement II: Methane can be broken down chemically

methane study of methane carbon- an important element hydrocarbons chemistry

  1. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1

  2. Both the Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1

  3. Statement 1 is correct but Statement 2 is not correct.

  4. Statement 1 is not correct but Statement 2 is correct.

  5. Both the Statement 1 and Statement 2 are not correct.

Show answer
Correct Option: A
Explanation:

Statement I: methane is defined as a compound
statement II: Methane can be broken down chemically
Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.
Note: Compounds are defined as substances of definite compositions which can be decomposed into two or more substances by a simple chemical process.

The correct composition of water gas is :

methane study of methane carbon- an important element hydrocarbons chemistry

  1. mixture of $H _2$ and $CO$

  2. mixture of $N _2$ and $CO$

  3. mixture of $He$ and $CO$

  4. mixture of $O _2$ and $CO$

Show answer
Correct Option: A
Explanation:

Water gas is produced from synthesis gas, which is composed of carbon monoxide and hydrogen. Syngas is a useful product, but requires careful handling due to its flammability and the risk of carbon monoxide poisoning. 

Reaction of methane with halogens under appropriate conditions is called as :

methane study of methane carbon- an important element hydrocarbons chemistry

  1. Halogenation

  2. Free radical halogenation

  3. Methylation

  4. Chlorination

Show answer
Correct Option: B
Explanation:

Methane reacts with halogens given appropriate conditions as follows:

${X} _{2} + UV \rightarrow  2 X \cdot$

$X \cdot + C{H} _{4} \rightarrow HX + C{H} _{3} \cdot$

$C{H} _{3} \cdot + {X} _{2} \rightarrow C{H} _{3}X + X \cdot$

where $X$ is a halogen: fluorine $\left(F\right)$, chlorine $\left(Cl\right)$, bromine $\left(Br\right)$, or iodine $\left(I\right)$. This mechanism for this process is called free radical halogenation.

Which are the gases formed in a biogas plant?

methane study of methane carbon- an important element hydrocarbons chemistry

  1. $CO, CH _{4}$

  2. $CH _{4}, CO _{2}$

  3. $CO _{2}, O _{2}$

  4. $N _{2}, S _{2}$

Show answer
Correct Option: A

Which of the following is not a derivative of carboxylic acids ?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. anhydrides

  2. esters

  3. amines

  4. amides

Show answer
Correct Option: C
Explanation:

C
Rest all are derivatives of carboxylic acids.And directly by the hydrolysis of amines carboxylic acids cannot be formed.

Which of the following cannot be named as a derivative of $CH _{3}COOH$?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. $CH _{3}CH _{2}COOH$

  2. $(CH _{3}) _{2}CHCOOH$

  3. $HCOOH$

  4. $(CH _{3}) _{3}CCOOH$

Show answer
Correct Option: C
Explanation:

Option A, B and D can be derived from $CH _3 COOH$ while option C, i.e., $HCOOH$ cannot be derived from $CH _3COOH$ as $HCOOH$ has one carbon less than $CH _3COOH$.


Option C is correct.

Which of the following statements is wrong?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. For the synthesis of esters from carboxylic acids and alcohols, we can often use a base as a catalyst.

  2. For the synthesis of esters from carboxylic acids and alcohols, we can often use an additional acid as a catalyst.

  3. For the alkaline hydrolysis of carboxylic esters, we need to use an excess of base.

  4. For the hydrolysis of carboxylic esters under acidic conditions, we need only a catalytic amount of an additional acid.

Show answer
Correct Option: A

With which of the following can ethyl ethanoate not undergo a substitution reaction?

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. $CH _3CO _2Na$

  2. aqueous $NaOH$

  3. $CH _3OH$, $H^+$

  4. aqueous $NH _3$

Show answer
Correct Option: A

Amides and acid chlorides are:

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. organic functional group

  2. functional derivative of carboxylic acid

  3. both $A$ and $B$

  4. none of these

Show answer
Correct Option: C
Explanation:

Amides and Acid chlorides are organic Functional group and functional derivative of carboxylic acid. Amide has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - NH _2  $. Carboxylic acid has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. An example of amide is acetamide $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - NH _2   $. An example of carboxylic acid is acetic acid $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. Acid chloride has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - Cl  $.  An example of acid chloride is acetyl chloride $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - Cl  $. 

As the molecular weight increases the boiling point of carboxylic acid:

acyl chlorides carboxylic acids and their derivatives functional derivatives of carboxylic acids carbonyl compounds chemistry

  1. increases

  2. decreases

  3. remain same

  4. none of the above

Show answer
Correct Option: A
Explanation:

As the molecular weight increases the boiling point of carboxylic acid increases. Lower aliphatic carboxylic acids (upto 9 C atoms) are liquids, the higher members are wax like solids.