Final answer:
To calculate the mass of the water, you can use the equation q = mcΔT and rearrange it to solve for mass. By plugging in the given values and the specific heat capacity of water, you can calculate the mass of the water.
Step-by-step explanation:
The heat absorbed by the water can be calculated using the equation q = mcΔT, where 'q' represents the heat absorbed, 'm' represents the mass of the water, 'c' represents the specific heat capacity of water, and 'ΔT' represents the change in temperature.
Given that the water absorbs 3.00 x 10^3 J of heat energy and the temperature change is 31.2°C - 20.0°C = 11.2°C, we can rearrange the equation to solve for mass: m = q / (cΔT).
Using the specific heat capacity of water (c = 4.184 J/(g·°C)), we can plug in the values to find the mass of the water:
m = (3.00 x 10^3 J) / (4.184 J/(g·°C) * 11.2°C).