Question

An aqueous solution of calcium chloride (CaCl2: MM=111.1g/mole) is 14% CaCl2 by mass. It has a density of 1.17g/ml.

a> determine the molality.

b> determine the freeing point of the solution (kf= 1.86 C/m)

c> determine the molarity of the solution.

d> how would the vapor pressure of this solution compare to that of pure water. Explain

Answer #1

molality = mol of S / kg solvent

assume: 100 g of solution

then

mass of CaCl2 = 100*0.14 = 14 g of CaCl2

mol of CaCl2 = masS/MW = 14/111.1 = 0.1260

kg of solvnet = (100-14)/1000 = 0.086

molal = 0.1260/0.086 = 1.4651 molal

b)

dTf = -Kf *m *i

i = 1+2 = 3 ions in solution

dtf = -1.86*1.4651 *3 = -8.175258

Tf = -8.175258 °C

d)

M = mol/V

mol = 0.1260

V = m/D = 100/1.17 = 85.470 ml

M = 0.1260 / ( 85.470/1000) = 1.474

d)

P° = Psolvent-xsolute*P°solvent

xsolute = mol S / (mol S + mol Water)

mol water = mass/MW = 86/18 = 4.777777

x = 0.1260 /(4.777777+0.1260 ) =0.0257

for water

assume T = 25°C

23.8 torr

then

P° = 23.8 -0.0257*23.8 = 23.18834 torr

An aqueous solution is 8.00% ammonium chloride, NH4Cl, by mass.
The density of the solution is 1.023 g/mL. What are the molality,
mole fraction, and molarity of NH4Cl in the solution?

An aqueous CaCl2 solution has a vapor pressure of 84.0 mmHg at
50 ∘C. The vapor pressure of pure water at this temperature is 92.6
mmHg. Part A What is the concentration of CaCl2 in mass
percent?

An aqueous CaCl2 solution has a vapor pressure of 80.8 mmHg at
50 ∘C. The vapor pressure of pure water at this temperature is 92.6
mmHg. What is the concentration of CaCl2 in mass percent?
I have done this multiple times and always get 47% but my prof
insists it is 23%. Could someone post a step by step so I can
compare my calculations? Thank you!

Calculate the molality, molarity, and mole fraction of FeCl3 in
a 23.0 mass % aqueous solution (d = 1.230 g/mL). molality=____m
molarity=____M mole fraction=___

Calculate the molality, molarity, and mole fraction of FeCl3 in
a 29.5 mass % aqueous solution (d = 1.280g/mL)

Commercially prepared concentrated HCl is an aqueous solution
that is 37.1% by mass HCl and has a density of 1.18 g/mL. (Water is
the solvent). Determine the molarity and molality of HCl in this
solution.

1. How many grams of calcium Chloride would be requird to be
added to 500.0 grams of water to ensure the freezing point would be
-2.5 degrees C? Given Kfim = ΔT
2. iff 222.8 grams of a non-volitile molecular compound lowers
the vapor pressure of pure water by 3.0 mmHg when made into 375.0
grams of water. What would be the Molar Mass of the unknown
compound given the vapor pressure of pure water at 30.0 degree C is...

Density of an aqueous calcium chloride solution is 1.23 g per
mL. If 30.0 grams of the solution are needed for a reaction, how
many mL of the CaCl2 solution should be poured into the reaction
vessel? (This question is about calculating
the volume if given the mass and density).
36.9 ml
0.0369 ml
0.0004 ml
24.4 ml
How many moles of magnesium, Mg, are there in 202 g of magnesium
oxide, MgO? Report your answer to 3 significant figures!...

1) Calculate the mole fraction of benzene and toluene in the
vapor in a solution of both with Xbenzene = 0.763. (At 25°C, the
vapor pressure of benzene is 96.0 mm Hg and 30.3 mm Hg for
toluene).
2) Calculate the freezing point of a solution prepared by
dissolving 15.0 g of Na2SO4 in 100 g of water. Kf for water is 1.86
°C.kg/mol.

The vapor pressure of water at 25 degrees Celsius is
23.76 mm of Hg; Kf for water is 1.86 (degree Celsius kg/mol). The
normal boiling point of chloroform is 61.0 degrees Celsius and Kb
is 3.63 (degree Celsius kg/mol) R=0.08206 (L atm/mol.k).
1. What is the vapor pressure of a solution on 10.0g of NaNO3 in
25.0g of water?
2. What is the freezing point of a 0.20 m
aqueous solution of sucrose at 1 atm pressure?
3. What is...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 6 minutes ago

asked 25 minutes ago

asked 26 minutes ago

asked 42 minutes ago

asked 51 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago