Covalent Bonding in Carbon Compounds MCQs

Q1. Which type of bond is present in a molecule of water?

• A.covalent bond
• B.ionic bond
• C.no bond
• D.metallic bond

Answer: A. covalent bond

Spot-the-setup - a typical chemistry numerical. We are after the quantity the stem asks for. Tool of choice - the mole concept: n = mass / molar mass and N = n * 6.022e23 particles per mole. Rearrange it for the unknown before substituting. Numbers in: the mole concept: n = mass / molar mass and N = n * 6.022e23 particles per mole → molar mass = sum of atomic masses (H=1, C=12, N=14, O=16). Common-sense check: substituting the data of the stem. Lock in option A) covalent bond. Trap-watch: option B) 'ionic bond' is wrong because Water is a covalent (polar) molecule; option C) 'no bond' misses the point - O and H share electrons covalently.

Q2. Which property is typical of covalent compounds?

• A.conduct electricity in solution
• B.always soluble in water
• C.very high melting points
• D.generally insoluble in water but soluble in organic solvents

Answer: D. generally insoluble in water but soluble in organic solvents

Q3. Why is the bond between carbon atoms strong?

• A.carbon has free electrons
• B.carbon atoms are very large
• C.carbon is small, so shared electrons are held tightly by the nuclei
• D.carbon forms ionic bonds

Answer: C. carbon is small, so shared electrons are held tightly by the nuclei

Asked for the unknown; data is laid out in the stem. By hence answer = carbon is small, so shared electrons are held tightly by the nuclei. the electron configuration fills shells in 2, 8, 8. Hence option C) carbon is small, so shared electrons are held tightly by the nuclei. Others fail: option A) 'carbon has free electrons' fails since Carbon shares electrons; the small size gives strong bonds; option B) 'carbon atoms are very large' doesn't hold - Carbon is small, giving strong bonds.