Question

Date: Section: Prelaboratory Assignment: An Introduction to Calorimetry 1. The metabolism of one mole of glycerol troleate, C,H,O, a common fat, produces 3.022 LU'J of heat. How many grams of the fat must be burned to raise the temperature of 50 g of water from 250 to 30 TC 2. A metal sample having a temperature of 100' and a mass of 45.2 g was placed in 50 g of water with a temperature of 26 C. At equilibrium, the final temperature was 32.7 C al How much heat flowed into the water? b) What is the heat capacity of the metal? What 3. When 2.0 p of NaOH are dissolved in 490 g of water, the temperature increased 10.5" is the seat of dissolution of Nail expressed in Joules per mole? 4. The heat capacity of copper is 0.382 Jig'. A 22.6 g sample of copper at 93 C is placed in 50 g of water at 23. What is the final temperature of the system'

Answer 1

Answer 1

According to calorimetry

q = m*c*∆T

c = 4.184 J g^-1 °C^-1 (heat capacity of water)

∆T = 30.0°C - 25.0°C = 5.0°C

m = 50 g

q = (50)(4.184)(5.0)

= 1046 J

= 1.046 kJ

Heat released by 1 mole of glycerol trioleate = 3.022 x 10⁴ kJ = 30220 kJ

Moles of required to be burned = (1.046 kJ)/(30220 kJ

= 0.0000366 mol

Molar mass of glycerol trioleate = 802.3 g

Mass of glycerol trioleate = (802.3 g/mol)*0.0000366 mol

= 0.0228 g

Answer 2

Heat flown to water = heat gained by water

= m*c*∆T

∆T = 32.7 - 26.0 = 6.7 °C

m = 50 g

c = 4.184 J g^-1 °C^-1

Heat gained by water = (50)(4.184)(6.7) = 1401.64 J

b)

Heat lost by metal = Heat gained by water

∆T for metal = 100 -32.7 = 67.3 °C

m = 45.2 g

Heat capacity of metal = C (to calculate)

1401.64 = (45.2)(C)(67.3)

C = 0.461 J g^-1 °C^-1