Question

How much energy (in kj) is required to heat 130.0 g h2o from a liquid at 54°c to a gas at 127°c?

Answer 1

To calculate the energy required to heat water from a liquid at one temperature to a gas at another temperature, you need to consider the energy required to heat the water, the energy required for the phase change, and the energy required to heat the water vapor. Given the specific heat of water and the enthalpy of vaporization, you can use these values in the calculations using the known values of mass and temperature provided in the question.

Step-by-step explanation:

To calculate the energy required to heat water from a liquid at one temperature to a gas at another temperature, we need to consider the following steps:

1. Calculate the energy required to heat the water from the initial temperature to its boiling point, using the equation Q = mcΔT, where Q is the energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.
2. Calculate the energy required for the phase change from liquid to gas, using the equation Q = nΔHvap, where Q is the energy, n is the number of moles, and ΔHvap is the enthalpy of vaporization.
3. Calculate the energy required to heat the water vapor from the boiling point to the final temperature, using the equation Q = mcΔT.
4. Sum up the energy from all three steps to get the total energy required.

Given the specific heat of water is 4.184 J/g °C and the enthalpy of vaporization is about 2,250 J per gram, we can use these values in the calculations using the known values of mass and temperature provided in the question.