Concentration Calculations/Solubility
A solution consists of 8.5 g of hydrogen sulfide(34 g/mol)dissolved in 95 g of water(18 g/mol).What is the mole fraction of hydrogen sulfide in this solution?
.045 x
The edge length of compound Jacobsonium (which is a body-centered cubic unit cell) is 5.84 x 10-8 cm; Jacobsonium has a density of 4.10 g/cm3. calculate the atomic weight (in g/mole) of Jacobsonium.
245.97 g/mol
Strongest Intermolecular force
Ion-Dipole
What is the change in the temperature of the freezing point (Tf) for a 5.0m solution of (NH4)2CO3 in water
(Kf=1.86°C/m)?
27.9 degrees Celsius
A solution consists of 0.95 g of ethanol (46 g/mol) dissolved in 11.0 mL of solution. a.What is the molarity of this solution? How many grams of ethanol are needed to make 15.4 mL of a solution with the same molarity?
1.91 M
1.33 g
Gold (MW: 196.97 g/mole) has a density of 19.32 g/cm3 and a unit cell side length of 4.08 Å. (1 Å
= 1 x 10-8 cm.)
How many atoms of gold are in one unit cell?
4 atoms
What is the strongest intermolecular interaction between CHCl3 and Cl2?
dipole induced dipole
From the data below, calculate the total heat (in J) released when converting 0.333 mol of gaseous
ethanol at 125 oC to liquid ethanol at 55.0 oC:
Boiling point of ethanol at 1 atm: 78.5 oC
ΔHvap= 40.5 kJ/mol
cgas = 65.8 J/mol . oC
cliquid = 78.7 J/mol . oC
-15.1 kJ
A solution consists of 4.7 g of ammonia (17 g/mol) dissolved in 300 g of water (18 g/mol).a.What is the molality of this solution?
.93 m
A Chemtastic element has a molar mass of 55.85 g/mole and forms a body-centered cubic unit cell with an edge length of 2.87x10-8cm. What is the density of this element? Note: 6.022x1023 atoms/mole
7.86 g/cm3
Which of the following would have the lowest vapor pressure?
A. H2S B. CH3CH2CH3 C. CBr4 D. I2
H2S
Kb(H2O) = 0.52 0C/m
Kf(H2O) = 1.86 0C/m
R = 0.0821 L atm/(mol K) = 8.314 J/(mol K)
DTb =i( Kb·m) DTf = i(Kf·m) Π = i(MRT) DP = i(Xsolute ´ P°solvent )
313 grams of NaCl (58.44 g/mole) were added to 765 grams of H2O (18 g/mole). What is the vapor pressure of this solution at 25°C if the vapor pressure of pure water at 25°C is 0.0313 atm?
.0243 atm
How many grams of ammonia (17 g/mol) should be added to 385 g of water to make a solution with a molality of .93 m ?
6.12 g
An unknown element Z has a density of 13.4 g/cm3 and forms a face-centered cubic unit cell with an edge length of 8.35x10-8cm. What is the molar mass of this element in units of g/mole? Note: 6.022x1023 atoms/mole
1175 g/mol
What is the intermolecular force between the two different particles if you have the following solution: H2S mixed with C2H6
dipole induced dipole
Pure water has a boiling point of 100°C and a Kb of 0.512 °C/m. A solution of MgCl2 was made by dissolving 112 grams of MgCl2 (95.2 g/mole) into 375 grams of water. What is the new boiling point for this solution?
109.58 degrees Celsius
A soft drink at 25°C consists of CO2dissolved in water. The Henry’s Law constant is 0.14 g/(100 g H2O ∙atm). How much CO2 is dissolved in 545 g of the soft drink, bottled at 3.8 atm of CO2?
2.9 grams
A naturally occurring gold crystallizes in face centred
cubic structure and has a density of 19.3 g cm 3.
Calculate the atomic radius of gold. (Au = 197 g/mol)
144 x 10-10 cm
What is the strongest type of intermolecular force between solute and solvent in the following
situations?
C10H22(l) in C12H26(l)
Dispersion
Tb =i( Kb·m) Tf = i(Kf·m) Π = i(MRT) P = I(Xsolute * Psolvent )
Which solution will have a higher boiling point: A solution containing 320 grams of sucrose
(C12H22O11 – 342 g/mole) in 620 grams of water or a solution containing 42 grams of MgCl2
(95g/mole) in 620 grams of water?
MgCl2 has a higher boiling point