In: Chemistry
Exactly 16.8 mL of water at 30.0 degrees celsius are added to a hot iron skillet. All of the water is converted into steam at 100 degrees celsius. The mass of the pan is 1.40 kg and the molar heat capacity of iron is 25.19 J/(mol*degree celsius). What is the temperature change of the skillet in degrees celsius?
density of water = 1 g/mL
specific heat capacity of water, C = 4.186 J/goC
latent heat of vaporization of water LV = 2264.76 J/g
mass of water= volume * density = 16.8 mL*1 g/mL = 16.8
g
Heat released by water = heat released when water is
converted from 30 oC to 100 oC + heat released to convert water to
steam
= m*C*delta T + m*Lv
= 16.8 * 4.186 * (100-30) + 16.8 * 2264.76
= 4922.74 + 38047.97
= 42970.71 J
Mass of iron = 1.4 Kg = 1400 g
Molar mass of iron = 55.85 g/mol
number of moles of iron,n = mass/ molar mass
=1400 / 55.85
= 25.07 mol
heat absorbed by iron = 42970.71 J
use:
Q = n*C'* delta T
42970.71 = 25.07 * 25.19 * delta T
delta T = 68 oC
Answer: 68 oC