Answer
During this condensation process, 4300 kcal of heat were released.
Work Step by Step
1. Identify the objective.
- Find the number of kilocalories that are necessary to condense 8.0 kg of steam at 100$^{\circ}$.
2. Find the conversion factors.
- To convert the mass in g to calories in a condensation process, we can use the Heat of Vaporization for water.
Page 79: $\frac{540cal}{1g}$ and $\frac{1g}{540cal}$
$1kcal = 1000cal$
$1kg = 1000g$
3. Using the conversion factor, calculate the necessary heat:
$8.0 kg \times \frac{1000g}{1kg} \times \frac{540cal}{1g} \times \frac{1kcal}{1000cal}= 4320 kcal$
4. Adjust the number to the correct number of significant figures.
- The used number that has the fewest number of significant figures is "8.0", with 2. Therefore, the result of the multiplication must have 2 SFs.
4320 kcal = 4300 kcal
5. Indicate whether heat was absorbed or released.
- During the condensation process, heat is released.
