Chemistry 9th Chap 14 : Topic 1 - Maryam Publications

Chemistry Chapter 14 : Topic 1

Alkanes and Saturation

1 / 18

Alkanes are described as saturated hydrocarbons because they contain a carbon skeleton in which each carbon atom forms single covalent bonds only, allowing the maximum number of hydrogen atoms to attach. Which statement best explains this property?

A) Alkanes always contain oxygen atoms in their structure.

B) Alkanes contain at least one double bond between carbon atoms.

C) Alkanes contain only single covalent bonds and cannot add more hydrogen atoms without breaking existing bonds.

D) Alkanes have carbon atoms bonded with hydrogen only through ionic bonds.

2 / 18

A student observes a hydrocarbon with molecular formula C₄H₁₀ and concludes it is an alkane. Which reasoning correctly supports this conclusion?

A) It has equal numbers of carbon and hydrogen atoms.

B) It contains a carbon-carbon triple bond.

C) It forms ionic compounds with metals.

D) It follows the general formula CₙH₂ₙ₊₂ indicating saturation.

3 / 18

In methane (CH₄), carbon forms four single covalent bonds. What does this indicate about carbon’s bonding nature in alkanes?

A) Carbon forms only ionic bonds in alkanes.

B) Carbon loses four electrons completely.

C) Carbon cannot bond with hydrogen.

D) Carbon shares electrons to complete its valency through single covalent bonds.

4 / 18

Which of the following best distinguishes alkanes from alkenes?

A) Alkanes contain only single covalent bonds and are saturated.

B) Alkanes are unsaturated and contain double bonds.

C) Alkanes react easily with bromine water without conditions.

D) Alkanes contain triple bonds between carbon atoms.

5 / 18

A hydrocarbon undergoes substitution reaction instead of addition reaction. What does this indicate about its structure?

A) It contains ionic bonding.

B) It contains a double bond.

C) It is saturated with only single covalent bonds.

D) It is an alcohol.

6 / 18

Which statement correctly explains why alkanes are called “saturated”?

A) They contain maximum possible hydrogen atoms bonded to carbon.

B) They are highly reactive due to double bonds.

C) They dissolve in water completely.

D) They contain oxygen atoms in all molecules.

7 / 18

Consider a hydrocarbon with only single bonds between carbon atoms and hydrogen atoms attached to carbon. What type of hydrocarbon is it?

A) Alkane

B) Alcohol

C) Alkyne

D) Alkene

8 / 18

Why are alkanes generally less reactive compared to alkenes?

A) They have only single covalent bonds with no weak double bonds.

B) They dissolve in acids.

C) They have strong ionic bonds.

D) They contain oxygen atoms.

9 / 18

The general formula of alkanes is CₙH₂ₙ₊₂. What does this formula indicate?

A) Formation of ionic compounds

B) Presence of double bonds

C) Saturation of carbon atoms with hydrogen

D) Presence of oxygen in structure

10 / 18

Which of the following hydrocarbons is definitely an alkane?

A) C₂H₂

B) C₅H₁₂

C) C₃H₆

D) C₂H₄

11 / 18

A teacher explains that alkanes cannot decolorize bromine water easily. What is the correct scientific reason?

A) They contain oxygen atoms.

B) They are saturated hydrocarbons with no double bonds.

C) They are soluble in bromine water.

D) They contain ionic bonds.

12 / 18

Which statement best describes bonding in alkanes?

A) Carbon atoms are joined by double covalent bonds.

B) Hydrogen atoms are not bonded to carbon.

C) Carbon atoms are joined by ionic bonds.

D) Carbon atoms are joined by single covalent bonds only.

13 / 18

Why does methane (CH₄) not show addition reactions?

A) It contains double bonds.

B) It contains oxygen atoms.

C) It has ionic bonding.

D) It is saturated with single covalent bonds only.

14 / 18

Which structural feature confirms a hydrocarbon is an alkane?

A) Presence of hydroxyl group

B) Presence of C=C bond

C) Presence of C≡C bond

D) Only C-C single bonds

15 / 18

A hydrocarbon is found to have maximum hydrogen atoms bonded to carbon atoms. What conclusion is correct?

A) It is an acid.

B) It is an alcohol .

C) It is unsaturated.

D) It is an alkane.

16 / 18

Which property is NOT associated with alkanes?

A) Saturated structure

B) High reactivity due to double bonds

C) Single covalent bonds

D) General formula CₙH₂ₙ₊₂

17 / 18

Why are alkanes classified as hydrocarbons?

A) They contain carbon and hydrogen only.

B) They contain metals and carbon.

C) They contain ions only.

D) They contain oxygen and hydrogen.

18 / 18

What happens if an alkane is forced to form more bonds than possible?

A) Existing bonds must break, showing saturation limit.

B) It forms ionic compounds.

C) It changes into an alkene.

D) It becomes more stable.

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