Class 10 Science Chapter 4 Practice Question Answers - Carbon and its compounds

Fill in the Blanks
Q1: Carbon forms covalent bonds primarily because it has _____ valence electrons in its outermost shell.
Ans: 4

Q2: The process of conversion of vegetable oils into solid fats is called ______.
Ans: Hydrogenation

Q3: Ethanol and methanol belong to the class of ______ alcohols.
Ans: Monohydric

Q4: The functional group present in carboxylic acids is ______.
Ans: -COOH (Carboxyl)

Q5: Polymers are formed by the repeated attachment of ______.
Ans: Monomers

Short Answer Questions
Q6: How is the property of catenation related to carbon?
Ans: The property of catenation allows carbon atoms to form long chains, branched structures, and rings due to its ability to form strong covalent bonds with other carbon atoms.

Q7: Give an example of an unsaturated hydrocarbon and explain its structure.
Ans: Ethene is an example of an unsaturated hydrocarbon. Its structure consists of a double bond between two carbon atoms, allowing for rotation around the single bonds and restricted rotation around the double bond.

Q8: Why is ethanol considered a renewable source of energy?
Ans: Ethanol is considered renewable because it can be produced from biomass such as sugarcane or corn, which are renewable resources. This makes ethanol a sustainable alternative to fossil fuels.

Q9: Define isomerism and provide an example involving carbon compounds.
Ans: Isomerism is the phenomenon where compounds have the same molecular formula but different structural arrangements. An example is butane and isobutane, both having the molecular formula C4H10 but different arrangements of carbon atoms.

Q10: How does the presence of a functional group affect the properties of organic compounds?
Ans: The presence of a functional group determines the chemical behavior and properties of organic compounds. For instance, the hydroxyl (-OH) functional group makes alcohols polar and capable of hydrogen bonding, affecting their solubility and boiling points.

Long Answer Questions

Q11: Describe the process of polymerization with an example of a synthetic polymer.
Ans: Polymerization is the chemical reaction in which small molecules called monomers join together to form long chains known as polymers. For instance, in the polymerization of ethene, multiple ethene monomers undergo addition reactions, forming a polyethylene chain.

Q12: Compare and contrast the structures of saturated and unsaturated hydrocarbons.
Ans: Saturated hydrocarbons (alkanes) contain single carbon-carbon bonds and have a straight or branched chain structure. Unsaturated hydrocarbons (alkenes and alkynes) contain at least one double or triple bond between carbon atoms, leading to restricted rotation and often a planar structure.

Q13: Explain the formation of a soap molecule using the process of saponification.
Ans: Saponification involves the hydrolysis of fats and oils by an alkali (such as sodium hydroxide) to form soap molecules. In this reaction, the ester linkage in triglycerides is broken, yielding soap molecules and glycerol as products.

Q14: Define homologous series and provide an example from the carbon compounds.
Ans: A homologous series is a group of organic compounds with the same functional group and similar chemical properties, but differing by a CH2 unit in their molecular formula. Example: Alkanes, where each member differs by -CH2- from the previous one.

Q15: Discuss the harmful effects of excessive carbon monoxide inhalation on human health.
Ans: Carbon monoxide (CO) is a colorless, odorless gas that binds to hemoglobin in red blood cells, reducing their ability to transport oxygen. This can lead to oxygen deprivation in tissues, causing symptoms like headache, dizziness, and in severe cases, even death.