An organic compound A having molecular formula C 2 H 4 O 2 reacts with sodium metal and evolves a gas B which readily catches fire. An also reacts with ethanol in the presentce of conc H 2 SO 4 TO form sweet smelling substance C used in making perfumes. i. Identify the compounds A, B, and C and write their names. ii. Write balanced chemical equations of represent conversion of a. compound A into compound B b. compound A into compound C iii. Write the chemical composition of detergents. Mention their advantage over soaps for washing clothes. OR i. What are hydrocarbons? Give one example. with two examples each. ii. Give the structural differences between started and unsaturated hydrocarbons iii. What is a functional group? Give examples of two different functional group.

Question

Philoid · Accepted Answer

i. A- Ethanoic Acid C₂H₄O₂

(Reason: Ethanoic acid or acetic acid is a weak carboxylic acid. acids react with alkali metals, hydrogen gas is produced)

B- hydrogen

(reason: hydrogen gas is released as an acid reacts with a metal)

C-Ester CH₃COOC₂H₅

(reason: Esters are sweet smelling substances formed when carboxylic acids react with alcohols. Here ethanoic acid reacts with ethanol.

ii. a. C₂H₄O₂+Na→CH₃COONa+H₂

B. C₂H₄O+C₂H₅OHCH₃COOC₂H₅

Important: To write equations in organic chemistry easily ,you need to learn the nomenclature of organic compounds and learn the properties of all the hydrocarbons and functional groups)

iii. Detergents are ammonium or sulphonate salts of long chain carboxylic acids.

Explanation : They are advantageous over soaps as-

• Hard water has carbonates and bicarbonates of calcium and magnesium. When soaps are used, the salts in hard water combine with soap and form a scum like substance which is hard to remove and sticks to the clothes. This defeats the very purpose of washing clothes, sigh. But when detergents do not have this scum problem. Therfore they are more preferable.

OR

i. A hydrocarbon is an organic compound consisting entirely of hydrogen and carbon.

Eg- methane, ethene etc.

ii. Saturated fats have no double bond between molecules, which means there are no gaps. But, in unsaturated compounds, there exists double bonds.

iii. An atom or group of atoms which show unique reactivity when treated with some reagents and impart unique chemical, and physical properties to the primary molecule, is defined as a functional group.

(Explanation: Functional groups are like different families and each family has different characteristics. Each family also have different names

Eg-alcohols, ketones and aldehydes.