Final answer:
The amount of heat needed to change 20g of water at 20 degrees Celsius is calculated using the formula Q = mcΔT, where Q is the heat energy, m is the mass of water, c is the specific heat capacity of water (4.184 J/g°C), and ΔT is the change in temperature.
Step-by-step explanation:
The student has asked how much heat is needed to change the temperature of 20g of water from 20 degrees Celsius to a different temperature. The concept here involves understanding the specific heat capacity of water and applying it to calculate the heat energy required for a particular mass of water to undergo a temperature change. Since the question does not specify the final temperature, we will consider a general scenario in which water at 20 degrees Celsius is heated to an arbitrary final temperature.
To find the amount of heat needed, the formula Q = mcΔT is used, where Q represents the heat energy in joules, m is the mass of the substance in grams, c is the specific heat capacity, and ΔT is the change in temperature in degrees Celsius.
Given that the specific heat capacity of water is 4.184 J/g°C, the calculation for a generic temperature change from 20°C to T degrees Celsius would be:
Q = (20g) * (4.184 J/g°C) * (T - 20°C). To solve for a specific scenario, simply replace T with the desired final temperature and calculate Q.