CHM 2045C Module Two Sample Exam ANSWERS
Module Two: Part G Temperature
Conversion 8
points
The general formula
for the conversion of temperatures on scale X to temperatures on scale Y is:
oY
= y units/ x units ( oX - RPx) + RPy
convert -196oC to oF
oF = 9 Funits/ 5 Cunits [ oC – (-40)]
+ (-40)
oF =
9/5 (-196 + 40) – 40 = 9/5 (-156) – 40 = -
280.5 -40 = -320.5 oF
convert -196oC to K
K = oC + 273
K = oC + 273 = -196 + 273
= 77 K
The Rankin scale uses a Fahrenheit
unit, but assumes zero to be absolute zero.
If absolute zero on the Kelvin scale is zero and on Celsius scale is
-273oC, calculate absolute zero on the Fahrenheit scale, then
estimate the Freezing point of water on the Rankin scale. (The BP water=212
oF=100
oC=373K= ?R)
oF
= 9 Funits/ 5 Cunits [ oC – (-40)]
+ (-40)
oF = 9/5 (-273 + 40) – 40 = 9/5 (-233) – 40 = - 419.4 -40
= -459.4 oF
absolute zero on
Rankin = 0 R equates to -459.6 oF therefore:
oR = 1 Runits/ 1 Funits [ oF
– (-459.4)] + 0
oR = 1 / 1 [ 32oF – (-459.4)] + 0
= 32 + 459.4 = 491.4 oF
Module Two: Part H
Density/Specific Gravity Calculations
8 points
A 25.0-mL sample of liquid bromine has
a mass of 78.0 g. What is the density
of bromine?
Density = mass/volume = 78.0
g / 25.0 mL = 3.12 g/mL
If a sugar solution weighs 4.678 gram
and has a volume of 4.670 ml, calculate the density of the solution.
Density = mass/volume = 4.678
g / 4.670 mL = 1.0017 g/mL
= 1.002 g/mL