31. Which of the following compounds has polar covalent bonds but is a nonpolar molecule?

a) H₂O
b) CO₂
c) NH₃
d) HCl
Answer: b) CO₂

32. Which of the following is an example of a molecule with hydrogen bonding?

a) CH₄
b) NH₃
c) CO₂
d) HCl
Answer: b) NH₃

33. In which compound are the atoms held together by covalent bonds?

a) NaCl
b) KBr
c) H₂O
d) MgO
Answer: c) H₂O

34. Which molecule has a T-shaped geometry?

a) SF₆
b) ClF₃
c) CH₄
d) NH₃
Answer: b) ClF₃

35. Which of the following statements is true about covalent bonds?

a) They involve the sharing of protons
b) They involve the transfer of electrons
c) They involve the sharing of electrons
d) They are formed between metals and nonmetals
Answer: c) They involve the sharing of electrons

36. The angle between the hydrogen atoms in a water molecule is approximately:

a) 90°
b) 104.5°
c) 120°
d) 180°
Answer: b) 104.5°

37. Which of the following molecules is most likely to exhibit hydrogen bonding?

a) H₂S
b) H₂
c) CH₃OH
d) CCl₄
Answer: c) CH₃OH

38. The hybridization of the central atom in phosphorus pentachloride (PCl₅) is:

a) sp
b) sp²
c) sp³
d) sp³d
Answer: d) sp³d

39. What is the molecular shape of methane (CH₄)?

a) Linear
b) Trigonal planar
c) Tetrahedral
d) Bent
Answer: c) Tetrahedral

40. Which bond is considered the weakest?

a) Covalent bond
b) Ionic bond
c) Hydrogen bond
d) Van der Waals forces
Answer: d) Van der Waals forces