What is an homologous series? Explain with an example.
What is an homologous series? Explain with an example.
Solution and Explanation
A homologous series is a series of carbon compounds that have different numbers of
carbon atoms but contain the same functional group.
For example, methane, ethane, propane, butane, etc. are all part of the alkane homologous series.
The general formula of this series is CnH2n+2.
Methane CH4
Ethane CH3CH3
Propane CH3CH2CH3
Butane CH3CH2CH2CH3
It can be noticed that there is a difference of −CH2 unit between each successive compound.
Top Questions on Chemical Properties Of Carbon Compounds
- (a) (i)Give reason why carbon can neither form C4+ cations nor C4− anions but form covalent compounds.
(ii) What is homologous series of carbon compound? Write the molecular formula of any two consecutive members of homologous series of aldehydes.
(iii) Draw the structure of the molecule of cyclohexane (C6H12).
OR
(b) (i) Name a commercially important carbon compound having functional group –OH and write its molecular formula. (ii) Write chemical equation to show its reaction with
(1) Sodium metal
(2) Excess conc. sulphuric acid
(3) Ethanoic acid in the presence of an acid catalyst
(4) Acidified potassium dichromate
Also write the name of the product formed in each case.- CBSE Class X - 2024
- Science
- Chemical Properties Of Carbon Compounds
- Consider the following statements about homologous series of carbon compounds:
(a) All succeeding members differ by –CH2 unit.
(b) Melting point and boiling point increases with increasing molecular mass.
(c) The difference in molecular masses between two successive members is 16 u.
(d) C2H2 and C3H4 are NOT the successive members of alkyne series.
The correct statements are –- CBSE Class X - 2024
- Science
- Chemical Properties Of Carbon Compounds
- Carbon compounds :
(i) are good conductors of electricity.
(ii) are bad conductors of electricity.
(iii) have strong forces of attraction between their molecules.
(iv) have weak forces of attraction between their molecules.
The correct statements are :- CBSE Class X - 2024
- Science
- Chemical Properties Of Carbon Compounds
Butanone is a four-carbon compound with the functional group
- CBSE Class X
- Science
- Chemical Properties Of Carbon Compounds
What is hydrogenation? What is its industrial application?
- CBSE Class X
- Science
- Chemical Properties Of Carbon Compounds
Questions Asked in CBSE X exam
- Which of the following statement(s) is (are) true about human heart?
(a) Right atrium receives oxygenated blood from lungs through pulmonary artery.
(b) Left atrium transfers oxygenated blood to left ventricle which sends it to various parts of the body.
(c) Right atrium receives deoxygenated blood through vena cava from upper and lower body.
(d) Left atrium transfers oxygenated blood to aorta which sends it to different parts of the body.- CBSE Class X - 2024
- Circulatory System
- Assertion (A): The rainbow is a natural spectrum of sunlight in the sky.
Reason (R) : Rainbow is formed in the sky when the sun is overhead and water droplets are also present in air.- CBSE Class X - 2024
- Light - Reflection and Refraction
- How does a physical activity facilitator maintain professional etiquettes?
- CBSE Class X - 2024
- Self-management Skills
- Assertion (A): The sum of the first fifteen terms of the AP $21, 18, 15, 12, \dots$ is zero.
Reason (R): The sum of the first $n$ terms of an AP with first term $a$ and common difference $d$ is given by: \[ S_n = \frac{n}{2} \left[ a + (n - 1) d \right]. \]- CBSE Class X - 2024
- Arithmetic Progression
- Give reasons for the following:
(i) Alveoli in lungs are richly supplied with blood capillaries.
(ii) Respiratory pigment in the blood takes up oxygen and not carbon dioxide.
(iii) During anaerobic respiration, a 3-carbon molecule is formed as an end product instead of CO2 in human beings.
OR
(i) Name the movements that occur all along the gut in human digestive system. How do they help in digestion?
(ii) Where is bile juice stored in human body? List two roles of bile juice.- CBSE Class X - 2024
- The respiratory system
Concepts Used:
Allotropes of Carbon
The existence of a chemical element in one or more physical forms happening in the same physical state is called Allotropes or allotropy. Allotropes may show different physical or chemical states turning on the atom arrangement or the number of existent atoms. While carbon and sulfur is the common element presenting allotropy. Carbon can make further allotropes due to its five-membered valency.
Read More: Allotropes of Carbon
Allotropes of Carbon:
Carbon is part of a p-block element.
- The atomic number of carbon = 6
- It belongs to group 14.
- It makes up about 18.5% of the human body by mass.
Carbon has only two types of allotropes, such as;
- Crystalline
- Amorphous
The crystalline form of carbon consists of allotropes like;
- Diamond
- Graphite
- Fullerenes
The amorphous form of carbon consists of allotropes like;
- Coal
- Coke
- Wood charcoal
- Animal charcoal
- Lampblack
- Gas carbon