Which of the following contains a coordinate bond?
A. O₃
B. NaCl
C. NH₃
D. H₂O
Answer: Option A
Solution (By JKExamLibrary)
Ozone (O₃) has a coordinate bond (dative bond). One oxygen atom donates a lone pair to another oxygen atom. The Lewis structure shows O=O⁺–O⁻ or resonance. NaCl is ionic; H₂O has polar covalent bonds; NH₃ has ordinary covalent bonds (though it can donate a lone pair to form coordinate bond in NH₄⁺).
Explanation:
To name this alkane, find the longest continuous carbon chain, which has 4 carbons (butane). Number the chain from the end closest to the substituent to give it the lowest possible number. The methyl group is on the second carbon. Thus, the IUPAC name is 2-methylbutane. Isopentane is its common name.
Explanation:
Ethane: H₃C-CH₃. There is one C-C single bond and six C-H single bonds, total 7 covalent bonds. Each bond is a sigma bond. The structural formula shows 7 bonds. Methane has 4, propane 10. Counting bonds is simple: each line represents a covalent bond.
Assertion (A): Detergents are more effective than soaps in hard water. Reason (R): Detergents do not form insoluble precipitates with calcium and magnesium ions.
A.A is false but R is true.
B.Both A and R are true and R is the correct explanation of A.
C.A is true but R is false.
D.Both A and R are true but R is NOT the correct explanation of A.
Explanation:
Soaps react with Ca²⁺ and Mg²⁺ ions in hard water to form insoluble scum (calcium/magnesium stearate), wasting soap and reducing cleaning efficiency. Detergents form soluble salts with these ions, so they lather well and clean effectively in hard water. Both statements are correct and R explains A.
No comments yet. Be the first to start the discussion!