Question

Using Raoult's law for water and Henry's law for nitrogen,
calculate the pressure and gas-phase composition (mole fractions)
in a system containing a liquid that is 1.200 mole% N_{2}
and 98.80 mole% water in equilibrium with nitrogen gas and water
vapor at 50.0°C.

The Henry's law constant for nitrogen in water is recommended by
NIST to be well represented by

*k*_{H} = 0.000625 exp[1300 (1/*T* –
1/298.15)] mol N_{2} / (kg H_{2}O bar), where
*T* is measured in Kelvin

a) Estimate the Henry's law constant *H* [atm/(mole
fraction N_{2})] for nitrogen in water at *T* =
50.0°C.

b) Estimate the nitrogen pressure in the gas phase using Henry's
law.

c) Estimate the vapor pressure of water using the Antoine
equation.

d) Estimate the total pressure using Raoult's law and Henry's
law.

e) Estimate the mole fraction of H_{2}O in the gas
phase.

Answer #1

It's a N2/water equilibrium system at 50 C where N2 is 1.2 mole % and 98.8 mole % in liquid state.

According to Henry Law,

K = 0.000625 exp[1300 (1/T – 1/298.15)] ( mole of N2 / mole H2O)(1/bar)

At t = 50 C or T = 323 K

Substitute value of T in above equation we get

K_{H} = 0.0004469 ( mole N2 /kg water ) (1/bar)

K_{H} = 0.0004469*(18/1000)(1/0.9869) mole fraction of
N2/ atm

= 8.15097 X 10^(-6) mole fraction of N2 / atm

K^{'}_{H} =
12.268 X 10^4 atm/mol fraction N2

(b) P =
K_{H}^{'} x

P = 12.2684 X 10^4 * (1.2/100)

P= 1472.25 atm

(C) Antoine equation constants for water are

A= 8.07131

B= 1730.63

C = 233.426

Vapor Pressure of water Pv at 50 C

= where t is in degree Celsius and P is in torr

Substituting values of A , B , C and t = 50 C

we get vapor pressure of water = 92.29 torr or 0.121 atm

1. The Henry's law constant for helium gas in water at 30 ∘C is
3.7×10−4M/atm; the constant for N2 at 30 ∘C is
6.0×10−4M/atm.
a. If helium gas is present at 2.1 atm pressure,
calculate the solubility of this gas.
b. If N2 is present at 2.1 atm pressure, calculate
the solubility of this gas.
2. A solution is made containing 14.7 g of CH3OH in 186 g
H2O.
a. Calculate the mass percent of CH3OH.
...

Use Henry's law and the solubilities given below to calculate
the total volume of nitrogen and oxygen gas that should bubble out
of 2.0 L of water upon warming from 25 ∘C to 50 ∘C. Assume that the
water is initially saturated with nitrogen and oxygen gas at 25 ∘C
and a total pressure of 1.0 atm. Assume that the gas bubbles out at
a temperature of 50 ∘C. The solubility of oxygen gas at 50 ∘C is
27.8 mg/L...

Calculate the partial pressure and gas-phase mole fraction of NO
in air that is in contact with water that has a mole fraction of
1.0(10)-6 NO. The temperature and pressure are
20oC and 1 atm.

1) Use Henry's law to determine the molar solubility of helium
at a pressure of 1.9 atm and 25 ∘C. Henry’s law constant for helium
gas in water at 25 ∘C is 3.70⋅10−4M/atm.
2) A 2.800×10−2M solution of NaCl in water
is at 20.0∘C. The sample was created by dissolving a sample of NaCl
in water and then bringing the volume up to 1.000 L. It was
determined that the volume of water needed to do this was 999.2 mL...

using viral equation of state, calculate pressure exerted by
4.56g of nitrogen gas in a vessel of volume 2.25L at 273 kelvin? B=
-10.5cm/mol

Chemistry - Gas Laws:
A 1.00 liter vessel contains 5.00 grams of nitrogen (N2) and
1.50 grams of water at 25°C.
a)Determine the RMS speed of nitrogen molecules and water
molecules in the vapor phase at 25°C.
b)Calculate the average kinetic energyper moleculeof nitrogen
and of water vapor at 25°C.
(Show all work and calculations, include units in
answer. If calculations must be used in several parts, rounding
should be made to 6 decimal points to ensure accuracy. Final
Answers...

A mixture of methane gas, CH4(g), and pentane gas, C5H12(g), has
a pressure of 0.5015 atm when placed in a sealed container. The
complete combustion of the mixture to carbon dioxide gas, CO2(g),
and water vapor, H2O(g), was achieved by adding exactly enough
oxygen gas, O2(g), to the container. The pressure of the product
mixture in the sealed container is 2.421 atm. Calculate the mole
fraction of methane in the initial mixture assuming the temperature
and volume remain constant. Xch4=

a) Use Henry's law to determine
the molar solubility of helium at a pressure of 1.8 atm and 25 ∘C.
Henry’s law constant for helium gas in water at 25 ∘C is
3.70⋅10−4M/atm.
Express your answer using two significant figures.
b) An aqueous solution containing 36.7 g of an
unknown molecular (non-electrolyte) compound in 160.0 g of water
was found to have a freezing point of -1.5 ∘C.
Calculate the molar mass of the unknown compound.
Express your answer using two...

1. Ammonia is being absorbed from nitrogen gas using water at 1
atm and 80° F. In the incoming N2, 45 kg/hr of ammonia are flowed
into the column, and the gas is 2 mass% ammonia. Henry’s constant
is 1.414. 99% of the incoming ammonia is absorbed in the water. a.
Assuming L/V=2Lmin/V, how many trays are required for separation?
b. Assuming L/V=4Lmin/V, how many trays are required for
separation?

The binary system, acetone(1)-acetonitrile(2) conforms closely
to Raoult’s Law.
a) Using the vapor-pressure data, prepare a graph showing P vs.
x1 and P vs. y1 at 50ºC, and a graph showing T vs. x1 and T vs. y1
at 400 mm Hg. Thus when T is fixed, x1 and y1 vary with P, and when
P is fixed, x1 and y1 vary with T.
b) The mixture which has an acetone mole fraction of 0.405 is
heated slowly (so as...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 2 minutes ago

asked 2 minutes ago

asked 8 minutes ago

asked 8 minutes ago

asked 9 minutes ago

asked 12 minutes ago

asked 13 minutes ago

asked 13 minutes ago

asked 14 minutes ago

asked 14 minutes ago

asked 14 minutes ago