Energy for melting equals mass times latent heat of fusion

Steps:

• Wax starts at melting point, so all 7700 J heats fusion only.
• Use formula: thermal energy Q = mass m × specific latent heat L.
• Rearrange: m = Q / L = 7700 J / 220 J/g.
• Compute: 7700 ÷ 220 = 35 g.

Why D is correct:

• D (35 g) exactly equals 7700 J divided by 220 J/g per Q = mL formula.

Why the others are wrong:

• A (0.59 g): Likely from inverting formula (220 / 7700, wrong units).
• B (1.7 g): Possible error dividing by ~4500 J/g (misread latent heat).
• C (12 g): Might subtract arbitrary value or use wrong specific heat instead.

Final answer: D