Tag: chemistry

Questions Related to chemistry

Identify the main functional derivative of carboxylic acid.

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

  1. Ester

  2. Alkane

  3. Alcohol

  4. None of these

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Correct Option: A
Explanation:

Ester is the main functional derivative of carboxylic acid. Ester has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OR'  $. Carboxylic acid has general formula $\displaystyle  R - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $. An example of ester is ethyl acetate $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - O-CH _2-CH _3  $. An example of carboxylic acid is acetic acid $\displaystyle  CH _3 - \underset {   \underset {\displaystyle O}{||}  }{C} - OH  $

Which of the following is acyl halide?

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

  1. $R-CO-X$

  2. $R-CO-O-CO-O-R$

  3. $R-COOH$

  4. $R-CO-NH _2$

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Correct Option: A
Explanation:

Acyl halide is $R-CO-X$
Hence option A is correct.

Identify the functional derivative of carboxylic acid.
$CH _3-CO-O-CO-CH _3$

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

  1. Amide

  2. Ester

  3. Acyl halides

  4. Acid anhydride

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Correct Option: D
Explanation:

An acid hydride is a compound that has two acyl groups $(CH _{3}COO)$ bonded to the same oxygen atom

Acyl halide and acid halide are same groups.

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

  1. True

  2. False

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Correct Option: A
Explanation:

The given statement is True.
Acyl halide and acid halide are same groups. They represent the function group
  $\displaystyle R- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-X$  where X is halogen atom (F, Cl, Br or I). They are derived from carboxylic acids (  $\displaystyle R- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-OH$ ) by replacing a hydroxyl group (-OH) with a halide group.
An example is acetyl chloride  $\displaystyle CH _3- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-Cl$
Another example is benzoyl chloride $\displaystyle Ph- \underset {\displaystyle  \underset {\displaystyle \text {O }}{||} }{C}-Cl$

Which of the following is/are the correct statement(s) about $C _{6}H _{5}COCl$?

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

  1. The IUPAC name of the compound is benzene carbonyl chloride

  2. The IUPAC name of the compound is benzylchloride

  3. It is an aromatic compound

  4. It is an aliphatic compound

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Correct Option: A,C

A salt is made by adding an excess of an insoluble metal oxide to an acid. How is the excess metal oxide removed from the mixture?

chemistry separation of substances mixtures: examples and properties types of solutions all about mixtures

  1. chromatography

  2. crystallisation

  3. distillation

  4. filtration

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Correct Option: D
Explanation:
$\text{Filtration is defined as the process of separating suspended solid matter from a liquid.}$$\text{ So it can be used to remove metal oxide from the mixture.}$

State True or False.
A mixture can not be represented by a chemical formula.

chemistry separation of substances mixtures: examples and properties types of solutions all about mixtures

  1. True

  2. False

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Correct Option: A
Explanation:

In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

Example of  a 'solid in liquid' mixture is :

chemistry separation of substances mixtures: examples and properties types of solutions all about mixtures

  1. oil in water

  2. muddy water

  3. smoke

  4. all of these

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Correct Option: B
Explanation:

 Phases of matter   Name of mixture  Examples
 Liquid - liquid  Emulsion  Oil in water
 Solid - liquid  Suspension  Muddy water
 Gas - liquid  Aerosol  Fizzy drinks
 gas - solid  Smoke  Smog

A mixture is a combination of two or more substances, where these substances are not bonded (or joined) to each other and no chemical reaction occurs between the substances.

Pick out the mixture from the following.

chemistry separation of substances mixtures: examples and properties types of solutions all about mixtures

  1. Water

  2. Oxygen

  3. Carbon dioxide

  4. Air

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Correct Option: D
Explanation:

Air is a mixture of gases in the atmosphere. Water is a compound, oxygen $(O _2)$is a molecule and carbon dioxide is also a compound.


Option $(D)$ is correct .

We separate mixtures to :

chemistry separation of substances mixtures: examples and properties types of solutions all about mixtures

  1. remove unwanted components

  2. to get pure substances

  3. Both of the above

  4. None of the above

Show answer
Correct Option: C
Explanation:

We separate mixture to remove the unwanted components and to get pure substances.