Exam 3 Extra Credit

Which is necessary to calculate the vapor pressure of a solution comprised of a volatile solvent and nonvolatile solute

The mole fraction of the solvent

The pKa values for H3PO4 are (numbers). Which of the following can be mixed to produce a buffered solution?

Includes H3PO4

The dissolution of a slightly solvable salt produces the conjugate base of an acid. The solubility of the salt…

Decreases as pH increases

Aqueous solution A (.01 M) is separated from aqueous solution B (.05 M) by a semipermeable membrane. Which is correct?

H2O molecules will move from solution A to solution B.

Which of the following statements is correct regarding solubility of AgF

Its solubility in .1 M AgNO3 is lower than it is in pure water

Which of the following is correct regarding emulsion

The continuous and dispersed phases are both liquid

The freezing point of an aqueous solution of 1 mol Na3PO4 in 1 kg water is

-7.44

In the dissolution of a salt that’s exothermic

As temp decreases the solubility of the salt should increase

Which has the lowest boiling point

.15 mole Mg(NO3)2

Which is correct regarding aqueous solutions pH at 25 C

For an acidic solution [H3O+] > 1 × 10-7 and pOH > 7

The Kb values are listed with big number, small number, middle number, list the strengths of their conjugate acids.

Small > middle > big

Which of the aqueous solutions is a buffer?

.1 M NaH2PO4 and .1 M K2HPO4. (Same back half with one less H in base)

Which is the weakest acid?

HBrO (least O)

Which titration will have a basic pH at equivalence point?

.1 M HC2H3O2 and .1 NaOH

When identifying a weak acid, based on titration with a strong base, what info is needed?

The pH at the midpoint of titration