1. Using your answer for question 4, what volume (in mL) would this amount of wa
ID: 911324 • Letter: 1
Question
1.
Using your answer for question 4, what volume(in mL) would this amount of water occupy when vaporized at 100oC and 1atm?
** Write answer in decimal fom to one decimal place. No units in answer.**
2.
An Erlenmeyer flask that weighs 93.667g has a quantity of liquid vaporized in it at 96.4oC and a pressure of 1583.8 torr. The mass of the cooled flask is 94.345g. When the flask is filled with water, the mass of the flask and water is 268.92g.
(a). Determine the molecular weight of the unknown liquid. g/mol ** Write answer in decimal form to one decimal place, NO units in answer**
(b). Given the following compounds:
Liquid Molecular Weight (g/mole)
Pentane 72.2
Acetone 58.1
Methanol 32.0
Hexane 86.2
Ethanol 46.1
Propanol 60.1
What is the identity of the unknown liquid?
Explanation / Answer
1. Using PV = nRT
V = nRT/P
we have,
n = 0.0166 mols
P = 1 atm
R = 0.08205 L.atm/K.mol
T = 100 oC = 100 + 273 = 373 K
Feed values,
V = 0.066 x 0.08205 x 373/1 = 2019..9
2. (a) Volume of water = g/density = 268.92g/1g/ml = 268.92 ml
moles of gas n = PV/RT
P = 1583.8 torr = 2.08 atm
T = 96.4 oC = 369.4 K
Feed values
n = 2.08 atm x 0.269/0.08205 x 369.4 = 0.0185 mols
molar mass = 1.654/0.0184 = 89.60 g/mol
Which is close to molar mass of hexane.
So the unknown liquid is Hexane.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.