Review - Chapter 1

Chem I | Chem II AP
Your score: 0%
1)
Which of the following cannot be an exact number?
2)
Round 20.589958 to 4, 3 and 2 significant figures, respectively.
3)
The solution to (22.41 + 0.464) x 999 / 18.465 is
4)
Calculate the mass of the earth in pounds if its mass is 3.7 x 1024 kg.
3.7 x 1024 kg x
2.2 lb
1 kg
= 8.1 x 1024 lb
5)
What are the dimensions, in metric units, for a linebacker who is 76.0 inches and 245 pounds?
76.0 in x
2.54 cm
1 in
= 193 cm x
1 m
100 cm
= 1.93 m
245 lbs x
1 kg
2.2 lb
= 111 kg x
1000 g
1 kg
= 1.11 x 105 g
6)
How many cubic centimeters are there in a cube whose edge is 4.2 yards in length?
4.2 yd x
36 in
1 yd
x
2.54 cm
1 in
= 384.048 cm on each side
V = lwh = (384.048)3 = 5.6644 x 107 = 5.7 x 107 cm3 (with 2 sig figs)
7)
58.0°F = ? °C
5/9 (°F - 32) = °C 5/9 (58 - 32) = 14.4°C
8)
Calculate the density, in kg/L, of a block of wood 2.5 ft x 18 in x 36 in that weighs 646 lbs.

There are two steps to this problem: change the mass to kg and the volume to L, then use the mass and volume to calculate density. Let's look at the unit conversions first:

Mass:646 lbs x
1 kg
2.2 lb
= 293.636 kg
Volume:
2.5 ft = 30 in
V = lwh
V = 30 in x 18 in x 36 in = 19440 in3 19440 in3 x
2.543 cm3
13 in3
x
1 mL
1 cm3
x
1 L
1000 mL
= 318.5645 L
Density:D =
M
V
=
293.636 kg
318.5645 L
= 0.921749 = 0.92 kg/L (with 2 sig figs)
9)
Which of the following is a pure substance?
10)
Which of the following is a homogeneous mixture?
11)
Which one of the following is the least desirable for separating sand and water?
12)
All of the following are pure substances, except:
13)
Which is a physical change?
14)
Which is not a physical property?
15)
Determine the sum of: 145.321 + 2.4

When adding and subtracting, round to the least number of places past the decimal.

16)
Which response lists all of the following properties of sulfur which are physical properties?
I. It reacts with hydrogen when heated
II. It is yellow solid at room temperature.
III. It is soluble in carbon disulfide.
IV. Its density is 2.97 g/mL.
V. It melts at 112°C.
17)
The following properties describe zinc. Which one(s) is/are chemical properties?
I. It is grey-white metal
II. It corrodes upon prolonged contact with moist air
III. Its density is 7.14g/cm3
IV. It melts at 419°C
V. It conducts electricity.
18)
Which response includes only chemical changes?
I. Souring of milk
II. Digestion of food
III. Condensation of steam
IV. Melting of silver
V. Burning of coal
19)
Which response lists only physical changes?
I. Evaporation of water
II. Fermentation of sugar
III. dissolving sugar in water
IV. Leaves changing color
V. Melting of gold
20)
Express 16.7 cubic feet in cubic centimeters.
16.7 ft3 x
123 in3
13 ft3
x
2.543 cm3
13 in3
= 472891 = 4.73 x 105 cm3 (with 3 sig figs)
or with the cubes worked out:
16.7 ft3 x
1728 in3
1 ft3
x
16.387 cm3
1 in 3
21)
25.0 g of Liquid A has a volume of 16.8 mL. 100.0 dg of Liquid B has a volume of 12.7 cm3. Which substance is more dense?
Liquid A: D =
25.0 g
16.8 mL
= 1.5 g/mL
Liquid B: 100 dg x
1 g
10 dg
= 10 g D =
10 g
12.7 mL
= 0.79 g/mL