Student query: Problem set

1 In which of the following compounds would you expect to find hydrogen bonding?
a: CH4

b: NH3

c: H2S

2 Concentrated nitric acid (HNO3 ) solution is a 72% by mass solution in water and has a density of 1.42g/cm3 . Determine the following

a: Molality of Nitric Acid

b: Molarity of Nitric Acid

c: Mole fraction of both experiments

3 The solubility of nitogen in blood is 5.60 X 10-4 m at 37.0° C and 0.800 atm N2 pressure. A diver makes a deep dive with a tank containing compressed air (Xn2 =
0.78) and is subjected to a total pressure of 5 atm. Answer the following:

a: What is the solubility of nitrogen in the divers blood at the bottom of the dive?

b: If you assume the mass of the divers blood is 5.0 kg, how many moles of nitrogen comes out of the divers blood when he comes to the surface?

c: How many ml of nitrogen gas comes out of the divers blood?

4 Trees that are able to withstand cold winter temperatures do so by removing water from the fluids within their biosystems, thus increasing the concentration of the solutes and lowering the freezing point of these fluids. If we assume that the tree sap is a sucrose (molecular weight = 342 g/mole) solution in water, what does the concentration of sucrose have to be for the tree to withstand -40.0° F winters?

5 A solution is prepared by dissolving 1.5203 g of sulfanilamide in 10.00g of a solvent called p-dichlorobenzene. The resulting solution freezes at 46.7° C. If the freezing point of p-dichlorobenzene is 53.1 C and has a K fp is 7.10° C/molal, what is the molecular weight of sulfanilamide?