Hello, I have attempted this question and was hoping to have some help.
This is the question:
Purpose: To plot the change of temperature due to the absorption of energy for a chemical as it changes phase from solid to liquid to gas.
Create a plot of temperature versus added energy in joules for a 1.0 g sample of ethanol over a temperature range of -180oC to 180oC. The relevant values for your calculations are:
sp. heat (solid) = 0.54 J/g.oC melting point = -114oC heat of vaporization = 854 J/g
sp. heat (liquid) = 2.44 J/g.oC boiling point = 78oC
sp. heat (gas) = 0.81 J/g.oC
heat of fusion = 104 J/g
1. Calculate the following amounts of energy:
(a) Joules to heat 1.0 g of solid ethanol from -180oC to -114oC
(b) Joules to melt 1.0 g of solid ethanol
(c) Joules to heat 1.0 g of liquid ethanol from-114oC to 78oC
(d) Joules to boil 1.0 g of liquid ethanol
(e) Joules to heat 1.0 g of gaseous ethanol from 78oC to 180oC
2. On graph paper, scale the x-axis in joules from 0 to 1600 (this should be the approximate total energy required). Scale the y-axis from -180 to 180
3. Make your plot with 5 distinct straight lines:
• Line 1: Joules increase by the amount in 1 (a); temperature increases from -180oC to -114oC.
• Line 2: Joules increase by the amount in 1 (b); no temperature increase (a straight line).
• Line 3: Joules increase by the amount in 1 (c); temperature increases from -114oC to 78oC
• Line 4: Joules increase by the amount in 1 (d); no temperature increase.
• Line 5: Joules increase by the amount in 1 (e); temperature increases from 78oC to 180oc.
****************************************************************************************
Ok so this is what I tried.
Should I keep all of the answers in KJ or is it ok to convert it to scientific notation? and if so, is it now in J?:
1. a)
1.0g x (-180 -(-114
oC)) x 0.54 J/g.
oC x 1KJ/10
3J
1.0g x (-66
oC) x 0.54 J/g.
oC x 1KJ/10
3J
0.03564 KJ
3.56 x 10
-2J
Did I do everything correct with the degrees? is it just -114? or -66?1. b)
1.0g x 104 J/g. x 1KJ/10
3J
= 0.104 KJ or 1.04 x 10
-11. c)
1.0g x (-114 -(78
oC)) x 2.44 J/g.
oC x 1KJ/10
3J
1.0g x (-36
oC) x 2.44 J/g.
oC x 1KJ/10
3J
Again did I do everything correct with the degrees? is it just 78? or do i subtract 78 from -114? i didn't do the answer because I'm unsure of the degrees1. d)
1.0g x (78
oC)) x 2.44 J/g.
oC x 1KJ/10
3J
= .190KJ or 1.90 x 10
-11. e)
Is this supposed be mass x heat of vaporization = heat or is it mass x :delta:t x sp.heat (gas) = heat? I completed the following in heat of vaporization 1.0g x (854 J/g x 1KJ/10
3J
= .854 KJ
8.54 x 10
-1J
For Part 3 do i just take the answers from part 1 and plot them on graph paper or are there other calculations I should do? For some reason the wording is not clear to me.
Thanks again for the help