5 Steps to a 5 AP Chemistry 2019

322 ❯ STEP 5. Build Your Test-Taking Confidence

56. What is the rate law expression for this reaction?
    (A) Rate = k[H 2 O 2 ] [I-]
    (B) Rate = k[HOI][I-]
    (C) Rate = k[H 2 O 2 ]
    (D) Rate =

I

IHHO

[]

[][][]

2

22

22

−+

57. A 30.00 g sample of metal (X) was heated to
    100.00°C. This sample was clamped in contact
    with a 40.00 g sample of a different metal (Y)
    originally at 25.00°C. The final temperature of
    the two metals was 37.30°C, and no heat was
    lost to the surroundings. What is one possible
    conclusion from this experiment?
    (A) The heat lost by X was greater than the
    heat gained by the Y.
    (B) The heat lost by X was equal to the heat
    gained by Y.
    (C) The heat lost by X was less than the heat
    gained by Y.
    (D) The final temperature was incorrectly
    determined, as it should be the average
    (62.50°C).

2-propanol

HCC

H

H

H

O

C H

H

H

HCC

H

H

C

2-pentanol

H

H

C

H

H

C

H

O

H

H

H

H

H

HCC

H

H

C

2-butanol

H

H

C

O

H

H

H

H

H

COMPOUND

BOILING

POINT (°C)

MOLAR MASS

(g MOL-^1 )

2-pentanol 118.9 88.15

2-butanol 99.5 74.14

2-propanol 82.4 60.11

58. Which of the following best explains why the boil-
    ing point of 2-propanol is lower than the other two
    compounds in the diagram and table above?
    (A) Larger molecules get tangled and cannot
    escape each other.
    (B) It has weaker hydrogen bonds.
    (C) It is the lightest of the three.
    (D) It is a more symmetrical molecule.

CH 3 CH 3

O H O

C C

O H O

59. The Dumas method is a procedure for determin-
    ing the molar mass of a gas. In this procedure the
    mass of a gas is divided by the moles of gas deter-
    mined from the ideal gas equation (n = PV/RT ).
    The molar masses of some compounds, such as
    acetic acid, illustrated above, show significant
    deviations from the “correct” values. Why does
    the presence of dimers as illustrated make it
    unlikely to obtain an accurate molar mass of
    acids, such as acetic acid?
    (A) Acetic acid, like all acids, will lose a hydro-
    gen ion, so the molar mass is that of the
    acetate ion, which is less than that of acetic
    acid.
    (B) Acetic acid is a liquid at room temperature,
    and its boiling point is too high to get
    accurate results.
    (C) Acids are too reactive to give accurate
    results.
    (D) The presence of strong intermolecular
    forces (hydrogen bonding) makes the gas
    nonideal; therefore the ideal gas law is not
    applicable.


60. In which of the following groups are the species
    listed correctly in order of increasing ionization
    energy?
    (A) Sr, Ca, Ba
    (B) Se, Tc, Ba
    (C) Mn, Fe, Ni
    (D) Cl, Br, I

STOP. End of AP Chemistry Practice Exam 1, Section I (Multiple Choice).

20-Moore_PE01_p307-340.indd 322 31/05/18 1:58 pm