Homework Chapter 1

The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses that distance in meters?

1.34 × 10^-10 m

Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas®, boils at 56.1°C. What is the boiling point in degrees Fahrenheit?

133°F

The appropriate number of significant figures in the result of 15.234 × 15.208 is

5

Which of the following correctly expresses 52,030.2 m in scientific notation?

5.20302 × 10^4 m

The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms?

5.5 × 10^-4 kg

Chemical Changes

Chemical changes always produce substances different from the starting materials.

As chief chemist at Superior Analytical Products (SAP) you must design an experiment to determine the density of an unknown liquid to three (3) significant figures. The density is of the order of 1 g/cm3. You have approximately 7 mL of the liquid and only graduated cylinders and balances are available for your use. Which of the following combinations of equipment will allow you to meet but not exceed your goal?

Graduated cylinder with ±0.01 mL uncertainty; balance with ±0.01 g uncertainty

A scientist made careful measurements of the pressure and temperature of many different gases. Based on these measurements, he concluded that "the pressure of a fixed amount of gas, measured at constant volume, is directly proportional to its absolute temperature." This statement is best described as a

Law

Physical Changes

Physical changes may be reversed by changing the temperature

You prepare 1000. mL of tea and transfer it to a 1.00 quart pitcher for storage. Which of the following statements is true?

The pitcher will be completely filled and a small amount of tea will overflow.

The most significant contribution to modern science made by alchemists was:

Their widespread acceptance of observation and experimentation.

A detailed explanation of natural phenomena that is generally accepted and has been extensively tested is called a

Theory

Which one of the following is a "substance" in the sense of the word as used in your textbook?

Water

Which of the following is an extensive property of oxygen?

mass

Which of the following abbreviations of the given SI base unit is incorrect?

mole: m

The appropriate number of significant figures in the result of 15.234 - 15.208 is

2.

At a pressure of one billionth (10-9) of atmospheric pressure, there are about 2.7 × 1010 molecules in one cubic centimeter of a gas. How many molecules is this per cubic meter?

2.7 × 10^16

Select the answer with the correct number of decimal places for the following sum: 13.914 cm + 243.1 cm + 12.00460 cm =

269.0 cm

Which of the following abbreviations of the given SI base unit is incorrect?

kelvin: k

The S.I. unit of speed (velocity) is

m/s

If the price of gold at the morning fixing in London was $5310 per lb, what would a kilogram of gold have cost in £ (pounds)? (Assume an exchange rate of $1.00 = £0.545)

£6370

Which one of the following numbers contains a digit or digits which is/are not significant?

.0043

The result of (3.8621 × 1.5630) - 5.98 is properly written as

0.06

Given that 1 inch = 2.54 cm, 1 cm3 is equal to

0.0610 in^3

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.)

1.840 g/cm^3

Which of the following represents the largest volume?

100 mL

The S.I. prefix mega- (M) means

10^6

Talc is a mineral that has low conductivity for heat and electricity and that is not attacked by acid. It is used as talcum powder and face powder. A sample of talc weighs 35.97 g in air and 13.65 g in mineral oil (d = 1.75 g/cm3). What is the density of talc?

2.82 g/cm^3

Which of the following correctly expresses 0.000007913 g in scientific notation?

7.913 × 10^-6 g

Express 96,342 m using 2 significant figures.

9.6 × 10^4 m

The difference between a student's experimental measurement of the density of sodium chloride and the known density of this compound reflects the ___________ of the student's result.

Accuracy

Which of the following is a chemical change?

Broiling a steak on a grill

Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm3, 4.67 g/cm3, 4.69 g/cm3, and 4.81 g/cm3. Independent studies found the correct density to be 4.75 g/cm3. Which of the following statements represents the best analysis of the data?

Bud's results have much greater accuracy than precision.

A dictionary has the following definition for a word: "A tentative explanation that accounts for a set of facts." Which of the following words best fits that definition?

Hypothesis

Which of the following activities is not a part of good science?

Indulging in speculation

The symbol for the S.I. base unit of mass is

Kg

During the swing of a frictionless pendulum, what energy form(s) remain constant?

Kinetic plus potential energy

Select the best statement about chemistry before 1800.

Lavoisier's quantitative work on the role of oxygen in combustion was the beginning of modern chemistry.

A student makes several measurements of the density of an unknown mineral sample. She then reports the average value of these measurements. The number of significant figures she uses in her result should be a measure of its

Precision.

Which of the following is not an S.I. base unit?

gram

The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cm3. What is that density in pounds per cubic inch?

0.491 lb/in^3

The average distance from Earth to the Sun is 150 megameters. What is that distance in meters?

1.5 × 10^8 m

Select the answer that expresses the result of this calculation with the correct number of significant figures and with correct units. 16.18 cm × 9.6114 g ÷ 1.4783 cm2 =

105.2 g/cm

The joule is the S.I. unit of energy, and is equal to 1 kg m2 s-2. The erg is another energy unit, equal to 1 g cm2 s-2. Use unit conversion methods to work out how many ergs are there in 1 joule.

10^7 ergs

Acetic acid boils at 244.2°F. What is its boiling point in degrees Celsius?

117.9°C

A dose of medication was prescribed to be 35 microliters. Which of the following expresses that volume in centiliters?

3.5 × 10^-3 cL

If the density of a certain spherical atomic nucleus is 1.0 × 1014 g cm-3 and its mass is 2.0 × 10-23 g, what is its radius in cm?

3.6 × 10^-13 cm

Isopropyl alcohol, commonly known as rubbing alcohol, boils at 82.4°C. What is the boiling point in kelvins?

355.6 K

A large pizza has a diameter of 15 inches. Express this diameter in centimeters.

38 cm

Which measurement is expressed to 4 significant figures?

62.40 g

Water vapor is less dense than ice because

Molecules in the gas phase have more space between them than in solids.

As part of an experiment to determine the density of a new plastic developed in her laboratory, Sara Ann Dippity measures the volume of a solid sample. Her four trials yield volumes of 12.37 cm3, 12.41 cm3, 12.39 cm3, and 12.38 cm3. Measurements of other scientists in the lab give an average volume of 12.49 cm3. Which of the following statements represents the best analysis of the data?

Sara's results have greater precision than accuracy.