Use ideal gas law to find molar mass Steps:

• Convert T to Kelvin: T = 100 + 273 = 373 K
• Calculate n = (P V) / (R T) = (1.013 × 10^5 × 4.50 × 10^{-3}) / (8.314 × 373) ≈ 0.147 mol
• M = m / n = 0.175 / 0.147 ≈ 119 g mol^{-1} Why C is correct:
• Matches M = (m R T) / (P V) from PV = nRT with n = m/M Why the others are wrong:
• A: From using T = 100 K (no °C to K conversion), yielding small M
• B: From using R = 0.0821 L atm mol^{-1} K^{-1} without unit conversion
• D: From rounding error in n or T calculation

Final answer: C