Final answer:
To calculate the mass of steam at 100°C required to be added to 357 g, we need to consider the heat absorbed during the phase change from liquid water to steam. The specific heat of water and the heat of vaporization for water are used in the calculation.
Step-by-step explanation:
In order to determine the mass of steam at 100°C that must be added to 357 g, we need to consider the heat absorbed during the phase change from liquid water to steam. The specific heat of water is 4.18 J/g°C, and the heat of vaporization for water is 40.7 kJ/mol.
First, we need to convert the mass of water to moles by dividing by the molar mass of water (18.015 g/mol). Then, we can calculate the heat absorbed by multiplying the moles of water by the molar heat of vaporization.
Let's assume that the water is pure, so the molar mass is the same as the mass of water.