Question

Oqwwuk-mdHzcULxl-A ADVANCED MATERIAL Madelyn Using heat of fusion or vaporization to find the heat needed to melt or boll a substance Calculate the amount of heat needed to boil 39.8 g of methanol (CH,OH), beginning from a temperature of 55.2 °C. Be sure your answer has a unit symbo and the correct number of significant digits ?

Answer 1

Step 1: Conversion of liquid methanol from 55.2°C to 64.7°C Mass of methanol = 39.8 g Heat capcity of methanol(l), c =2.47 — ge Change in temperature, 47 = 64.7°C-55.2°C= 9.5°C Amount of heat required, qı = mcAT = 39.88 * 2.47 E-x(9.5°C) = 934 J = 0.934 kJ Step 2: Conversion of methanol from 64.7°C to 64.7°C Mass of methanol = 39.8 g Molar mass of methanol = 32.04 g/mol Heat of vaporization of methanol = 35.278 kJ/mol 1 mol 35.278 kJ Amount of heat required, 92 = 39.8g X2 $ 32.04 g 1 mol = 43.8 kJ Total amount of heat required, q = 91 +92 = 0.934 kJ+ 43.8 kJ = 44.734 kJ = 44.7 kJ