Given the data below, calculate the total heat (in J) needed to convert 20.0 g of liquid ethanol (C2H5OH) at 40.0 oC to gaseous ethanol at 125 oC.

A. 3.23 x 103 B. 3.67 x 103 C. 4.17 x 103 D. 2.08x104 E. 2.12 x 104

It would have helped to give the data below. Here is how you do the problem.

I assume there is a density. Use the density to calculate the mass. mass -= volume x density.

Then for heat used there are two formula to use.
Within a phase you use
mass x specific heat x (Tfinal-Tinitial)
For example, for liquid ethanol between the freezing point and boiling point you will use
mass ethanol x specific heat ethanol x (b.p. temp - freezing point temp).

Then for the change of phase use
mass ethanol x heat fusion at the melting/freezing point or
mass ethanol x heat vaporization at the boiling point.

Then add all of the heats together for the total.
Post your work if you get stuck.

To solve this problem, we need to use the heat 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 (in J/g°C), and
ΔT is the change in temperature (in °C).

First, we need to calculate the heat energy required to raise the temperature of the liquid ethanol from 40.0 °C to its boiling point.

The specific heat capacity for ethanol is approximately 2.44 J/g°C.

Q1 = mcΔT1
= (20.0 g)(2.44 J/g°C)(125.0 °C - 40.0 °C)
= 20.0 g)(2.44 J/g°C)(85.0 °C)
= 4168 J

Next, we need to calculate the heat energy required to convert the liquid ethanol at its boiling point to gaseous ethanol at 125 °C.

The heat required to change the state of a substance is given by its heat of vaporization. For ethanol, the heat of vaporization is approximately 846 J/g.

Q2 = mL
= (20.0 g)(846 J/g)
= 16920 J

Finally, we can calculate the total heat energy required by summing up Q1 and Q2.

Total heat energy = Q1 + Q2
= 4168 J + 16920 J
= 21088 J

Therefore, the total heat energy required to convert 20.0 g of liquid ethanol at 40.0 °C to gaseous ethanol at 125 °C is approximately 21088 joules.

The correct answer is option E: 2.12 x 104 J.