Chapter 22:
New Materials Through Chemistry
Practice Test
1.
Because of improvements in manufacturing techniques, the number of transistors and other components per mm
2
on an integrated circuit has doubled, on average, every two years. If integrated circuits contained 100,000 transistors in 1982, estimate how many transistors an integrated circuit of the same size contained in 1998.
a.
1,600,000
b.
25,600,000
c.
800,000
d.
2,560,000
Hint
2.
To reduce weight, many car parts are made of plastic instead of steel. A certain car contains 200 kg of parts made of plastic instead of steel, and the density of steel is twice the density of plastic. If the volume of the plastic parts equals the volume of the same parts made of steel, by how many kilograms is the mass of the car reduced by using plastic parts instead of steel?
a.
100 kg
b.
400 kg
c.
200 kg
d.
800 kg
Hint
3.
The molecules in a sample of polypropylene have an average length of 60,000 monomers. The monomer of polypropylene has the formula CH
2
CHCH
3
. What is the mass, in amu, of a polypropylene molecule made of 60,000 monomers? Express your answer in scientific notation.
a.
2.52 × 10
6
amu
b.
2.52 × 10
7
amu
c.
5.40 × 10
5
amu
d.
6.00 × 10
4
amu
Hint
4.
A certain process for manufacturing integrated circuits packs 47,600,000 transistors into an area of 340 mm
2
. If this process is used to produce integrated circuits with an area of 1 cm
2
, how many transistors would these integrated circuits contain? Express your answer in scientific notation.
a.
1.4 × 10
8
transistors
b.
1.40 × 10
7
transistors
c.
1.62 × 10
10
transistors
d.
1.40 × 10
5
transistors
Hint
5.
Eight measurements are made of the melting point of a stainless steel alloy. Rounded to the nearest degree, the measured values are 1,421 °C, 1,420 °C, 1,421 °C, 1,423 °C, 1,423 °C, 1,421 °C, 1,424 °C, and 1,419 °C. What is the mode of these measurements?
a.
1,421 °C
b.
5 °C
c.
1,419 °C
d.
1,424 °C
Hint
6.
A 14-karat gold earring has a mass of 10 g. What is the mass of gold the earring contains?
a.
5.8 g
b.
4.2 g
c.
1.4 g
d.
0.58 g
Hint
7.
In 1997, about 6,400,000,000 kg of polyvinyl chloride were used in the United States. About 6% of the PVC used was for packaging. How many kilograms of PVC were used in 1997 for packaging? Express your answer in scientific notation.
a.
3.84 × 10
8
kg
b.
1.0 × 10
9
kg
c.
3.84 × 10
10
kg
d.
9.4 × 10
8
kg
Hint
8.
The melting point of a new aluminum alloy is measured on five different samples. The measured values of the melting point are 631.5 °C, 632.3 °C, 636.1 °C, 637.4 °C, and 630.2 °C. What is the mean of these measurements?
a.
630.2 °C
b.
632.3 °C
c.
637.4 °C
d.
633.5 °C
Hint
9.
Stainless steel is an alloy of iron, chromium and nickel. A stainless steel spoon contains 30.0 g of iron, 6.8 g of chromium, and 3.2 g of nickel. What percentage of the stainless steel is chromium?
a.
22.7%
b.
10.7%
c.
20.5%
d.
17.0%
Hint
10.
Measurements are made of the copper content of 7 bronze buttons found at an archaeological site. The measured values are 83%, 90%, 91%, 72%, 79%, 87%, and 89%. What is the median of these measurements?
a.
91%
b.
72%
c.
87%
d.
79%
Hint
