5 Steps to a 5 AP Chemistry

190  Step 4. Review the Knowledge You Need to Score High

9. To prepare 3.0 L of a 0.20-molar K 3 PO 4 solution
   (molecular weight 212), a student should follow
   which of the following procedures?

(A) The student should weigh 42 g of solute and

add sufficient water to obtain a final volume

of 3.0 L.

(B) The student should weigh 42 g of solute and

add 3.0 Kg of water.

(C) The student should weigh 130 g of solute

and add sufficient water to obtain a final

volume of 3.0 L.

(D) The student should weigh 42 g of solute and

add 3.0 L of water.

(E) The student should weigh 130 g of solute

and add 3.0 L of water.

10.A 5.2 molal aqueous solution of methyl alcohol,
CH 3 OH, is supplied. What is the mole fraction
of methyl alcohol in this solution?

(A) 0.10

(B) 0.19

(C) 0.086

(D) 0.050

(E) 0.094

11.Choose the aqueous solution with the highest
boiling point.

(A) 0.10 M HI

(B) 0.10 M (NH 4 ) 3 PO 4

(C) 0.20 M C 2 H 5 OH

(D) 0.10 M NH 4 Cl

(E) 0.10 M NaI

12.How many grams of MgSO 4 (molar mass
120.4 g/mol) are in 100.0 mL of a 5.0-molar solution?

(A) 600 g

(B) 5.0 g

(C) 12 g

(D) 60.0 g

(E) 120 g

13.How many milliliters of concentrated nitric acid
(16.0-molar HNO 3 ) are needed to prepare 0.500 L
of 6.0-molar HNO 3?

(A) 0.19 mL

(B) 250 mL

(C) 375 mL

(D) 190 mL

(E) 100 mL

14. I. the molal freezing-point constant, Kf, of the
    solvent

II. the freezing point of the pure solvent and the

freezing point of the solution

When using the freezing-point depression method

of determining the molar mass of a nonelectrolyte,

what information is needed in addition to the above?

(A) the mass of the solute

(B) the volume of the solvent and the mass of the

solute

(C) the mass of the solvent and the boiling point

of the solvent

(D) the mass of the solvent and the mass of the

solute

(E) no additional information is needed

15.A student has a solution with a mole fraction of

0.20 of chloroform (molecular mass 119.4) in

carbon tetrachloride (molecular mass 153.8). What

is the molality of chloroform in the solution?

(A) 1.7 m

(B) 0.17 m

(C) 0.20 m

(D) 1.3 m

(E) 1.20 m

16.A solution is 10 percent urea by mass. Which

item(s) from the following list are needed to cal-

culate the molarity of this solution?

I. the density of the solution

II. the density of the solvent

III. the molecular weight of urea

(A) I and III

(B) I only

(C) II only

(D) III only

(E) I and II

17.Which of the following aqueous solutions would

have the greatest freezing-point depression?

(A) 0.10 m (NH 4 ) 2 SO 4

(B) 0.10 m MnSO 4

(C) 0.10 m NaF

(D) 0.10 m KCI

(E) 0.10 m CH 3 OH