Library Guides: Chemistry Textbook: Self-Assessments

1. Matter and Measurements
2. Atoms, Molecules and IonsToggle Dropdown
3. Composition of Substances and SolutionsToggle Dropdown
4. Stoichiometry of Chemical ReactionsToggle Dropdown
5. ThermochemistryToggle Dropdown
6. GasesToggle Dropdown
7. Chemical Bonding and Molecular GeometryToggle Dropdown
8. Liquids, Solids, and Modern MaterialsToggle Dropdown
9. Solutions and Colligative PropertiesToggle Dropdown
10. KineticsToggle Dropdown
11. Chemical Equilibria and ApplicationsToggle Dropdown
12. ThermodynamicsToggle Dropdown
13. ElectrochemistryToggle Dropdown
14. AppendicesToggle Dropdown

Chapter-1 Self Assessments

Classification- matter and properties
Significant digits
Metric Conversions
Units Conversions- area and volume
Worded Problems

Which of the following is NOT matched correctly?

Choose 1 answer

Vinegar: homogenous mixture

Graphite: element

Water: compound

Tungsten: compound

Bromine gas: element

Vinegar is typically 5-8% acetic acid. It contains water and acetic acid and has uniform composition. So, vinegar is a homogeneous mixture.

Graphite is composed of only carbon atoms. So, graphite is an element

Water molecules are composed of hydrogen and oxygen atoms. So, water (H₂O) is a compound.

Tungsten (W) is an element, made of only one kind of atoms. Note that Tungsten appears on the periodic table of elements.

Bromine molecules (Br₂) are composed of only bromine atoms. So, bromine is an element. Note that Bromine appears on the periodic table of elements.

Which of the following is NOT matched correctly?

Choose 1 answer

Solid Iodine: element

Chicken noodle soup: heterogenous mixture

Aluminum carbide: homogenous mixture

Rock: heterogenous mixture

Gold: element

Iodine (I₂) molecules are composed of only Iodine atoms. So, Iodine is an element. Note that Iodine appears on the periodic table of elements.

Chicken noodle soup contains more than one substance which makes it mixture. Since, the composition is not uniform throughout, it is a heterogeneous mixture.

Aluminum carbide is a single substance. It is composed of more than one kind of atoms (aluminum and carbon). It is a compound.

A rock is a mixture because it contains more than one substance--several minerals and organic matter. The composition is not uniform throughout. Hence, it is a heterogeneous mixture.

Gold (Au) is an element, made of only one kind of atoms. Note that Gold appears on the periodic table of elements.

Which of the following is NOT an extensive property?

Choose 1 answer

Density

Mass

Volume

Length

Energy

Density is mass per unit volume. No matter how much substance you have, mass per milliliter will be a constant for the substance. Since density is independent of amount of substance, it is an intensive property. Note that ratio of two extensive properties will be intensive.

Mass depends on amount of substance, so, it is an extensive property.. A larger quantity will weigh more.

Volume depends on amount of substance, so, it is an extensive property. A larger quantity will occupy more space.

Length depends on amount of substance, so it is an extensive property. Example, larger amount of rope will have greater length.

Energy depends on amount of substance, so it is an extensive property. Example, a larger quantity of food contains greater energy.

Which of the following is a chemical change?

Choose 1 answer

sublimation of iodine

apple turning brown

magnetizing iron

mixing sand and water

boiling water

Sublimation is the process of a substance changing it's state from solid to gas, without passing through the liquid state. The distance between the molecules increases greatly during this change of state. However, no new substances are formed, so, sublimation is a physical change.

When an apple turns brown, say by exposing it to air, a chemical reaction called oxidation occurs due to the reaction of oxygen with the chemical substances (polyphenols) in the apple's flesh. New substances are formed in the process, so, it is a chemical change. The chemical reaction can be simplified to: Polyphenol Oxidase + O₂ &arr; Melanin (Brown Color)

When a substance is magnetized, it atoms align in the direction of the magnetic field. No new substances are formed in the process, so, it is a physical change.

Sand and water do not react. Mixing them does not generate new substances, so, it is a physical change.

When a substance boil's, it changes from liquid state to gaseous state. The distance betwen the water molecules increases greatly when water changes from liquid to gaseous state. However, no new substance is created in the process, so, boiling is a physical process.

Which of the following is a NOT a chemical change?

Choose 1 answer

rusting of iron

digestion of food

Iron reacting with hydrochloric acid

condensation of steam

combustion of propane

Rusting is a chemical process because iron, oxygen and water react together to create new substance (hydrated form of ferric oxide) commonly known as rust.

During digestion, food is broken down into smaller molecules. The process involves formation of new substances, so, it is a chemical process.

Iron and hydrochloric acid react together to form new substances (iron chloride and hydrogen gas). Since new substances are formed in the process, it is a chemical change.

Steam is water in vapor state. The identity (ie. chemical composition) of water does not change during condensation; it just changes state from gas to liquid, and no new substances are formed. Therefore, it is a physical process.

During combustion of a fuel, the fuel reacts with oxygen to produce other gaseous substances such as carbondioxide and water vapor. Since new substances are formed, combustion is a chemical change.

How many significant digits are in the following quantity?
0.0050 cm

Choose 1 answer

All zeroes in a measurement may not be significant. Review how to count significant digits here.

Some of the decimal zeroes in this example are leading zeroes. Review how to count significant digits here.

Review how to count significant digits here.

There are three leading zeroes, one non-zero digit and a trailing zero in this number that has a decimal point. Review Topic.

Review how to count significant digits here.

Which of the following quantities has 4 significant digits?

Choose 1 answer

3500 cm

0.03000 cm

0.035 cm

3.50 × 10⁵ cm

3010 cm

This number has 2 significant digits. Review how to count significant digits here.

There are two leading zeroes, one non-zero digit and three trailing zeroes in this number that has a decimal point.
Review Topic.

This number has 2 significant digits. Review how to count significant digits here.

This number has 3 significant digits. The 10⁵ merely indicates the location of the decimal point.

This number has 3 significant digits. Review how to count significant digits here.

How many significant digits should be in the result to the following calculation?
99.350 cm + 8.4 cm

Choose 1 answer

When adding or subtracting numbers, round the result to the same number of digits as the number with the least number of decimal places, not signficant digits.
How many decimal places will be in the result? How many significant digits?

When adding or subtracting numbers, round the result to the same number of digits as the number with the least number of decimal places, not signficant digits.

When adding or subtracting numbers, round the result to the same number of digits as the number with the least number of decimal places.
How many decimal places will be in the result? How many significant digits?

The result should be rounded to one decimal place, which will amount to four significant digits.

When adding or subtracting numbers, round the result to the same number of digits as the number with the least number of decimal places.

What is answer to the following calculation after it is rounded to the appropriate number of significant digits?
12 cm x 9.80 cm

Choose 1 answer

200 cm²

120 cm²

118 cm²

110 cm²

12 cm²

When multiplying or dividing numbers, round the result to the same number of digits as the number with the least number of significant figures.

The result is rounded up to 2 significant digits and zero is used a placeholder in this case.

When multiplying or dividing numbers, round the result to the same number of digits as the number with the least number of significant figures.

There are correct number of significant digits in the answer, but it has not been rounded correctly. Review Significant Figures in Calculations.

12 x 9.800 cannot be just 12! You must use a placeholder.

How many significant digits should be in the answer to the following calculation?
(0.973 x 35.44) - 0.43

Choose 1 answer

Review significant digits in calculations.

Paranthesis should be evaluated first, followed by subtraction.

Parenthesis is evaluated first:
For multiplication:
0.973 (3 sig figs)
x 35.44 (4 sig figs)
= 34.48312 (round to 3 sig figs).
Three significant digits in 34.48312 is equivalent to 1 decimal place.

Next, we evaluate the subtraction
For substraction:
34.48312(rounded to 1 decimal)
- 0.43 (2 decimals)
= 34.05312 (round to 1 decimal) = 34.1
The result, therefore, has three significant digits.

Paranthesis should be evaluated first, followed by subtraction.

Review significant digits in calculations.

What are the two ways to express the conversion factor between decimeter (dm) and meter (m)?

Choose 1 answer

1 dm = 10¹ m or 1 dm = 10^-1 m

1 dm = 10^-1 m or 1 m = 10¹ dm

1 dm = 10² m or 1 dm = 10^-2 m

1 dm = 10^-2 m or 1 dm = 10² m

1 dm = 10³ m or 1 dm = 10^-3 m

Review metric prefixes here.

The prefix, deci means one-tenth. A decimeter is tenth of a meter (1 dm = 0.1 m); or, a meter has ten decimeters (1 m = 10 dm)
Note: In scientific notation, negative exponent beside larger unit or positive exponent beside smaller unit.

Review metric prefixes here.

3.05 g = ___________________ µg (g)

Choose 1 answer

3.05 × 10⁹

3.05 × 10^-9

3.05 × 10⁶

3.05 × 10^-6

3.05 × 10³

Review metric prefixes here.

Gram is a larger unit than a microgram. Review metric prefixes here.

Conversion factor: 1 µg = 10^-9 g or, 1g = 10⁹ µg
Gram is larger than a microgram. So, grams contain lots of micrograms. The answer should be a big number, ie. positive exponent in the scientific notation.

Gram is a larger unit than a microgram. Review metric prefixes.

Review metric prefixes here.

The wavelength of green light is 5.5 x 10^-4 mm. What is the wavelength in nanometers?

Choose 1 answer

5500 nm

550 nm

55 nm

5.5 x 10⁶ nm

5.5 × 10^-8 nm

Review metric prefixes here.

mm → m → nm.
Conversion factors: 1 mm = 10^-3 m; 1 nm = 10^-9 m.
Review metric prefixes here.

Review metric prefixes here.

Millimeter is larger than nanometers. There should be lots of nanometers in a the given amount of millimeters; but, the value you chose is very small! Review metric prefixes here.

The mirrors in the Weber telescope are coated with gold to increase the reflectivity of the telescope in infrared light.
The thickness of the gold coating is 100 nm. What is the thickness in centimeters?(g)

Choose 1 answer

1 × 10¹³cm

1 × 10⁷ cm

1 × 10^-7 cm

1 × 10^-5 cm

1 × 10⁵ cm

Convert nm → m → cm. Review metric prefixes here.

Conversion factors to use are: 1 nm= 10^-9 m, and, 1 cm = 10^-2 m.
Or you may convert nm to cm directly using 1 nm = 10^-7cm.

Convert nm → m → cm. Review metric prefixes here.

The SI unit of power is watt (W).
1.9 Gigawatt = ______________ Kilowatt. (g)

Choose 1 answer

1.9 x 10⁹

1.9 x 10^-3

1.9 x 10³

1.9 x 10^-6

1.9 x 10⁶

Review metric prefixes here.

Conversion factors: 1 GW = 10⁹ W and 1 KW = 10³ W.

A computer chip has a surface area of 4.1 × 10⁴ square centimeters. What is it’s area in square inches?

Choose 1 answer

6.4 × 10³ in²

1.6 × 10⁴ in²

1.0 × 10⁵in²

2.6 × 10⁵ in²

2.6 × 10⁸ in²

A cm² is cm x cm. Both should be converted to inches to obtain in². Review topic here.

Conversion factor used: 1 in² = 2.54² cm².

Error in conversion factor. Review topic here.

You may have squared the given number as well. Only conversion factor must be squared. Review topic here.

in² is larger than cm². When converting to a larger unit, you should end up with a smaller number than what is given. Review topic here.

The pressure of a gas is 35.6 lb/in². What is the pressure in kg/m². (g)

Choose 1 answer

2.51 x 10¹⁰ kg/m²

1.04 x 10⁶ kg/m²

1.04 x 10^-2 kg/m²

2.51 x 10⁴ kg/m²

3.09 x 10^-3 kg/m²

Possible error in metric conversion factors.

Check calculation. You may have not used paranthesis in the calculator.

It is possible you treated m² as if it is in the numerator during dimensional analysis.
Write kg over m² with a horizontal bar so you see which unit is in the numerator and which one in the denominator clearly.

Plan: lb/in² → g/in² → kg/in² → kg/cm² → kg/m².
Conversion factors: 1 lb = 454 g; 1000 g = 1 kg; 1 in² = 2.54² cm²; 100² cm² = 1 m².

Possible error in in² to cm² conversion factor.

The capacity of a gas tank in an automobile is 13.2 gal. What is the volume in m³?
1 gal = 3.785 L

Choose 1 answer

5.00 m³

5.00 × 10^-2 m³

3.49 × 10^-2 m³

3.49 × 10^-3 m³

0.349 m³

Possible error while converting Liters to m³; convert via dm³ or cm³. Review topic here.

gal → L → dm³ → m³. Conversion factors: 1 L = 1 dm³, 10³ dm³ = 1 m³ (Note that the conversion factor between m and dm is cubed).
You may also convert gal → L → mL → cm³ → m³

Convert gal → L → dm³ → m³. Review conversion factors for volume here.

A cube has a side of 1.6 inches. What is the volume of the cube in Liters?

Choose 1 answer

6.7 × 10⁴ L

4.0 × 10^-2 L

6.7 × 10^-2 L

4.0 × 10^-3 L

1.2 × 10^-3L

Review conversion factors for units of volume here.

Volume of a cube = (length)³. Review conversion factors for units of volume here.

Volume = (length)³ = (4.0 cm)³ = 64 cm³Convert cm³ → mL → L

Volume of a cube = (length)³. Review conversion factors for units of volume here.

The density of a substance is 8.96× 10^-3 g/mm³. What is it’s density in kg/L?

Choose 1 answer

8.96 kg/L

0.896 kg/L

0.0896 kg/L

0.00896 kg/L

Perform dimensional analysis converting one unit at a time, taking note whether the unit to be converted is in the numerator or denominator.
g/mm³ → kg/mm³ → kg/dm³ → kg/L
(Note: you may convert mm³ to dm³ via the base unit, m³ (ie. mm³ → m³ → dm³. Remember to cube the conversion factors for length to obtain conversion factors for volume)

Hint: mm³ should be converted to L via either cm³ or dm³. Review conversion factors for units of volume here.

An airplane averaged 450 miles per hour on a trip. What was it’s speed in feet per second?
(1 mi = 1.609 km
12 in = 1 ft
1 in = 2.54 cm)

Choose 1 answer

660 ft/s

6600 ft/s

6.6 × 10³ ft/s

66 ft/s

6.6 ft/s

Perform dimensional analysis converting units in the numerator and denominator, one at a time.
mi/hr → km/hr → m/hr → cm/hr → in/hr → ft/hr → ft/min → ft/s

Perform dimensional analysis converting units in the numerator and denominator, one at a time. Review Topic.

You are buying carpet to cover a room that measures 38 ft by 40 ft. The carpet costs $18 per square yard. How much will the carpet cost?
1 yd = 3 ft

Choose 1 answer

$912

$820

$602

$523

$304

Area = length × width = 38 ft × 40 ft = 1520 ft². Use dimensional analysis to go from ft² to $. Review conversion factors for areas and volume

Area = length × width = 38 ft × 40 ft = 1520 ft². Use dimensional analysis to go from ft² to $. Review conversion factors for areas and volume
ft² → yd² → $
Conversion factors: 1 yd² = 9 ft²; 1 yd² = 18$

Area = length × width = 38 ft × 40 ft = 1520 ft²

An average human heart beats 60 times per minute. If the average person lives to the age of 86, how many times does the heart beat in a lifetime?

Choose 1 answer

1,400,000,000

2,700,000,000

3,500,000,000

6,200,000,000

7,100,000,000

hHint: Given unit: 86 yr Desired unit: beats
Conversion factor from the problem statement: 60 beats = 1 min;

86 yr → day → hr → min → beats.
Conversion factors: 60 beats = 1 min; 1 year = 365 days; 1 day = 24 hr; 1 hr = 60 min

Hint: Given unit: 86 yr Desired unit: beats
Conversion factor from the problem statement: 60 beats = 1 min

Hint: Given unit: 86 yr Desired unit: beats
Conversion factor from the problem statement: 60 beats = 1 min;

Hint: Given unit: 86 yr Desired unit: beats.
Conversion factor from the problem statement: 60 beats = 1 min;

A smelting company uses steel ingots, each weighing 500 lb, to manufacture ball bearings. Three ingots can be melted to produce 450 ball bearings. How many metric tons of ingots are needed to produce a million ball bearings?
1 kg = 2.2 lb
1000 kg = 1 metric ton

Choose 1 answer

7.3 × 10⁹ tons

7.3 × 10³ tons

730 tons

1.5 × 10⁹ tons

1.5 × 10³ tons

Hint:Given unit: 10⁶ ball bearings Desired unit: tons
Other conversion factors are stated in the problem.

Hint: Given unit: 10⁶ ball bearings Desired unit: tons
Other conversion factors are stated in the problem.

Hint:Given unit: 10⁶ ball bearings Desired unit: tons
Other conversion factors are stated in the problem

Hint: Given unit: 10⁶ ball bearings Desired unit: tons
Other conversion factors are stated in the problem

6 ball bearings → ingots → lb → kg → ton
Other conversion factors: 3 ingots = 450 ball bearings; 1 ingot = 500 lb

Gasoline has a fuel value of 48 kilojoules per gram. How much energy in joules can be obtained by filling an automobile’s 16.3-gallon tank with gasoline, assuming gasoline has a density of 0.70 kg/dm³?
1 gal = 3.785 L

Choose 1 answer

2.1 × 10⁹ Joules

2.1 × 10⁶ Joules

2.1 × 10³ Joules

4.2 × 10⁸ Joules

4.2 × 10⁵ Joules

16.3 gal → L → dm³ → kg → g → kilojoules → joules

Hint:
Given unit: 16.3 gal Desired unit: Joules

A manometer is a device used to measure pressure.
A 50.00 pound flask of mercury costs $132.50. The density of mercury is 383.24 kg/ft ³. It takes 4.950 in ³ of mercury to make 2 manometers. Find the price of the mercury used to make 25 manometers.

Choose 1 answer

$80.17

$72.14

$64.50

$56.10

$11540

25 manometers (or devices) → in³ → ft³ → kg → lb → $
To convert in³ → ft³, cube 12 in = 1 ft. (that is, 12³ in³ = 1 ft³)

Hint Given: 25 manometers or 25 devices Desired unit: $
Conversion factors from the problem: 2 manometers = 4.950 in³
1 ft³ = 383.24 kg
50.00 lb = $132.50

Hint Given: 25 manometers or 25 devices Desired unit: $
Conversion factors from the problem: 2 manometers = 4.950 in³
1 ft³ = 383.24 kg
50.00 lb = $132.50
Perhaps you made a mistake in converting in³ to ft³

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Chemistry Textbook

Chapter-1 Self Assessments

Which of the following is NOT matched correctly?

Which of the following is NOT matched correctly?

Which of the following is NOT an extensive property?

Which of the following is a chemical change?

Which of the following is a NOT a chemical change?

How many significant digits are in the following quantity? 0.0050 cm

Which of the following quantities has 4 significant digits?

How many significant digits should be in the result to the following calculation? 99.350 cm + 8.4 cm

What is answer to the following calculation after it is rounded to the appropriate number of significant digits? 12 cm x 9.80 cm

How many significant digits should be in the answer to the following calculation? (0.973 x 35.44) - 0.43

What are the two ways to express the conversion factor between decimeter (dm) and meter (m)?

3.05 g = ___________________ µg (g)

The wavelength of green light is 5.5 x 10-4 mm. What is the wavelength in nanometers?

The mirrors in the Weber telescope are coated with gold to increase the reflectivity of the telescope in infrared light. The thickness of the gold coating is 100 nm. What is the thickness in centimeters?(g)

The SI unit of power is watt (W). 1.9 Gigawatt = ______________ Kilowatt. (g)

A computer chip has a surface area of 4.1 × 104 square centimeters. What is it’s area in square inches?

The pressure of a gas is 35.6 lb/in2. What is the pressure in kg/m2. (g)

The capacity of a gas tank in an automobile is 13.2 gal. What is the volume in m3?1 gal = 3.785 L

A cube has a side of 1.6 inches. What is the volume of the cube in Liters?

The density of a substance is 8.96× 10-3 g/mm3. What is it’s density in kg/L?

An airplane averaged 450 miles per hour on a trip. What was it’s speed in feet per second?(1 mi = 1.609 km12 in = 1 ft1 in = 2.54 cm)

You are buying carpet to cover a room that measures 38 ft by 40 ft. The carpet costs $18 per square yard. How much will the carpet cost? 1 yd = 3 ft

An average human heart beats 60 times per minute. If the average person lives to the age of 86, how many times does the heart beat in a lifetime?

A smelting company uses steel ingots, each weighing 500 lb, to manufacture ball bearings. Three ingots can be melted to produce 450 ball bearings. How many metric tons of ingots are needed to produce a million ball bearings?1 kg = 2.2 lb1000 kg = 1 metric ton

Gasoline has a fuel value of 48 kilojoules per gram. How much energy in joules can be obtained by filling an automobile’s 16.3-gallon tank with gasoline, assuming gasoline has a density of 0.70 kg/dm3?1 gal = 3.785 L

A manometer is a device used to measure pressure. A 50.00 pound flask of mercury costs $132.50. The density of mercury is 383.24 kg/ft 3. It takes 4.950 in 3 of mercury to make 2 manometers. Find the price of the mercury used to make 25 manometers.

How many significant digits are in the following quantity?
0.0050 cm

How many significant digits should be in the result to the following calculation?
99.350 cm + 8.4 cm

What is answer to the following calculation after it is rounded to the appropriate number of significant digits?
12 cm x 9.80 cm

How many significant digits should be in the answer to the following calculation?
(0.973 x 35.44) - 0.43

The wavelength of green light is 5.5 x 10^-4 mm. What is the wavelength in nanometers?

The mirrors in the Weber telescope are coated with gold to increase the reflectivity of the telescope in infrared light.
The thickness of the gold coating is 100 nm. What is the thickness in centimeters?(g)

The SI unit of power is watt (W).
1.9 Gigawatt = ______________ Kilowatt. (g)

A computer chip has a surface area of 4.1 × 10⁴ square centimeters. What is it’s area in square inches?

The pressure of a gas is 35.6 lb/in². What is the pressure in kg/m². (g)

The capacity of a gas tank in an automobile is 13.2 gal. What is the volume in m³?
1 gal = 3.785 L

The density of a substance is 8.96× 10^-3 g/mm³. What is it’s density in kg/L?

An airplane averaged 450 miles per hour on a trip. What was it’s speed in feet per second?
(1 mi = 1.609 km
12 in = 1 ft
1 in = 2.54 cm)

You are buying carpet to cover a room that measures 38 ft by 40 ft. The carpet costs $18 per square yard. How much will the carpet cost?
1 yd = 3 ft

A smelting company uses steel ingots, each weighing 500 lb, to manufacture ball bearings. Three ingots can be melted to produce 450 ball bearings. How many metric tons of ingots are needed to produce a million ball bearings?
1 kg = 2.2 lb
1000 kg = 1 metric ton

Gasoline has a fuel value of 48 kilojoules per gram. How much energy in joules can be obtained by filling an automobile’s 16.3-gallon tank with gasoline, assuming gasoline has a density of 0.70 kg/dm³?
1 gal = 3.785 L

A manometer is a device used to measure pressure.
A 50.00 pound flask of mercury costs $132.50. The density of mercury is 383.24 kg/ft ³. It takes 4.950 in ³ of mercury to make 2 manometers. Find the price of the mercury used to make 25 manometers.