What is the total number of joules of heat needed to change 300 g of water to steam at 100 degrees C?*

6.78 × 10⁵ J

Explanation:

Step 1: Given and required data

Step 2: Calculate the heat (Q) required to vaporize 300 grams of water

We will use the following expression.

Q = ΔH°vap × m

Q = 2260 J/g × 300 g

Q = 6.78 × 10⁵ J

6.78 × 10⁵ Joule will be required to convert 300 g of water to steam at 100 °C.