Question

Suppose that 0.88g of water condenses on a 75.0-g block of iron that is initially at 22 degrees Celsius. If the heat released during condensation goes only to warming the block, what is the final temperature (in degrees Celsius) of the iron block? Assume a constant enthalpy of vaporization for water of 44.0 kJ/mol.

Answer 1

The final temperature (in degrees Celsius) of the iron block is 85.82 °C

Step-by-step explanation:

Determine the heat emitted by the condensing water.

qw = 0.88 g H2O
`(1 mol H2O)/(18.0152 g H2O)`
`(- 44 kJ)/(1 mol H2O)`

qw = -2.1492 kJ

Determine the heat absorbed by the iron block

qw = - qw = - (-2.1492 kJ) = 2.1492 kJ

Look up the specific heat for iron. Use the specific heat equation to solve for the final temperature of the iron block.

q = mcΔT

ΔT = q / mc

Temp f = (q / mc) + Temp i

Temp f = 2.1492 x 10^3 J / 75 g (0.449 J/g.°C) + 22 °C

Temp f = 85.82 °C