how many joules of energy are needed to change 275 g of water from 15 degrees C to steam at 100 degrees C?
q1 = heat needed to raise temperature of liquid water from 15 C to 100 C.
q1 = mass x specific heat H2O x (Tfinal-Tinitial)
q2 = heat need to convert H2O at 100 C to steam at 100 C.
q2 = mass H2O x heat vaporization.
To find the amount of energy needed to change the temperature of water from 15 degrees Celsius to steam at 100 degrees Celsius, we need to consider two processes: heating the water from 15 degrees Celsius to 100 degrees Celsius, and then converting it from liquid to steam.
Let's break down the problem into two steps:
Step 1: Heating the water from 15 degrees Celsius to 100 degrees Celsius
The heat energy required to increase the temperature of a substance can be calculated using the equation:
Q = mcΔT
Where:
Q is the heat energy (in joules),
m is the mass of the substance (in grams),
c is the specific heat capacity of the substance (in joules/gram degrees Celsius), and
ΔT is the change in temperature (in degrees Celsius).
The specific heat capacity of water is approximately 4.18 joules/gram degree Celsius. Let's calculate the heat energy required to heat 275 g of water from 15 degrees Celsius to 100 degrees Celsius:
Q1 = (275 g) * (4.18 J/g°C) * (100°C - 15°C)
Step 2: Converting the water to steam
To convert water from its liquid state to steam at its boiling point, we need to consider the heat energy required for phase transition. This can be calculated using the equation:
Q2 = mL
Where:
Q2 is the heat energy (in joules),
m is the mass of the substance (in grams), and
L is the latent heat of vaporization (in joules/gram).
The latent heat of vaporization for water is approximately 2260 joules/gram. Let's calculate the heat energy required to convert 275 g of water to steam:
Q2 = (275 g) * (2260 J/g)
Now, we can calculate the total energy required to change 275 g of water from 15 degrees Celsius to steam at 100 degrees Celsius by adding up the heat energies from both steps:
Total energy = Q1 + Q2
I'll perform the calculations for you.