Assertion (A): Covalent compounds generally have low melting points. Reason (R): The intermolecular forces in covalent compounds are weak compared to ionic compounds. MCQ with Answer and Explanation
Assertion (A): Covalent compounds generally have low melting points. Reason (R): The intermolecular forces in covalent compounds are weak compared to ionic compounds.
A. Both A and R are true but R is NOT the correct explanation of A.
B. A is true but R is false.
C. A is false but R is true.
D. Both A and R are true and R is the correct explanation of A.
Answer: Option D
Solution (By JKSSB Mock Tests)
Covalent compounds consist of molecules held together by weak van der Waals forces, unlike the strong electrostatic forces in ionic lattices. Therefore, less heat energy is required to break these intermolecular forces, resulting in low melting and boiling points. Both statements are true and R correctly explains A.
Explanation:
One carbon atom with four hydrogens is methane (CH₄). Ethane is C₂H₆, propane C₃H₈. Methanol is CH₃OH (alcohol). Methane is the simplest alkane.
Explanation:
Fractional distillation is the primary separation method in refining. Cracking breaks larger hydrocarbons into smaller ones (gasoline). Reforming alters structure to improve octane rating. Polymerisation combines small molecules. Fractional distillation separates based on boiling points in a fractionating column.
Explanation:
Baking powder = sodium bicarbonate + weak solid acid (usually tartaric acid or cream of tartar). On moistening, they react to produce COâ‚‚, causing dough to rise without requiring external acidic ingredient.
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