This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Practice Midterm 20B 1. If 2.00 mol of an ideal gas at 25°C expands isothermally and reversibly from 9.00 L to
36.00 L, calculate the work done on the gas and the heat absorbed by the gas in the
process. 2. The following table gives several points on the pressuretemperature diagram of
ammonia: ——— Use this information to sketch the phase diagram of ammonia. 3.
a.) Please list the following species in order of increasing root—meansquare speed at 298 K and explain the trend:
Xe, H2, N2 b.) What would be the kinetic energy of the above species? c.) The mean speed of CO molecules with MW 28.0 g/mol is 476 m s‘1 at 300 K. What
will the mean speed of these molecules be at 400 K? 4. The vapor pressure of pure liquid ethanol, CZHSOH (MW 46.1) at 25°C is 71.0 torr.
The speciﬁc freezing point depression constant Kf for ethanol is 1.22 kg mol“. Pure
liquid ethanol freezes at —115°C. When 40.0 grams of an unknown solute is dissolved in 100.0 grams of ethanol, a solution
is formed whose volume is 165.0 ml (25°C). The pressure of ethanol vapor in
equilibrium with this solution at 25°C is 60.1 torr. Assuming Raoult’s Law, ﬁnd the
following: a.) the mole fractions of ethanol and of the unknown solute in the solution.
b.) the molecular weight of the unknown solute
c.) the freezing temperature of the solution. 5. Calculate the pressure exerted by 0.5000 mol N2 in a 1.000 L container at 25°C. a.) using the ideal gas law
b.) using the van der Waals equation of state.
(a = 1.39 atm LZ/molz, b = 0.0391 L/mol) ...
View
Full Document
 Winter '08
 FELKER

Click to edit the document details