Practice Test 1

There are 45 practice questions in the practice exam. Select the correct answers and the exam will be automatically graded. For those problems where there are no answers given, do the problems and write down the answers, and check the answers when they are given at the end.

Which one of the following is a “substance” in the sense of the word as used in your text book?

air

tap water

sea water

water

E.	George W. Bush

2.	Give an example of a physical property and a chemical property of each of the following: a. oxygen gas b. octane c. copper Answer:

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/cm³at the temperature of the measurement.)

A.	1.992 g/cm³

B.	1.840 g/cm³

C.	1.729 g/cm³

D.	1.598 g/cm³

E.	0.543 g/cm³

The area of a 15-inch pizza is 176.7 in². Express this area in square centimeters.

1140. cm²

448.8 cm²

96.8 cm²

69.57 cm²

27.39 cm²

Select the best statement about chemistry before 1800.

A.	Alchemy focused on objective experimentation rather than mystical explanations of processes.

B.	The phlogiston theory laid a valuable theoretical basis for modern chemistry.

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

D.	The interpretation of data by alchemists was not biased by their overall view of life.

E.	Alchemists failed because they did not develop any practical chemical methods.

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?

159°F

133°F

101°F

69.0°F

43.4°F

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

A.	proposing a theory

B.	developing a hypothesis

C.	making quantitative observations

D.	designing experiments

E.	indulging in speculation

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?

A.	849 lb/in³

B.	490 lb/in³

C.	376 lb/in³

D.	0.491 lb/in³

E.	1.83 × 10^-3lb/in³

Select the best statement.

A.	Chemical changes provide the only valid basis for identification of a substance.

B.	Chemical changes are easily reversed by altering the temperature of the system.

C.	Chemical changes always produce substances different from the starting materials.

D.	Chemical changes are associated primarily with extensive properties.

E.	Chemical changes are accompanied by changes in the total mass of the substances involved.

10.

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

16.4 in³

6.45 in³

0.394 in³

0.155 in³

E.	0.0610 in³

11.

The weight of a coin measured as 1.96235 g on one balance is definitely more accurate than a weight measurement of 1.95 g on another balance.

True

False

12.

Calculate the numerical part of the conversion factors needed to carry out the following unit conversions:
a. density in g/cm³ to kg/m³
b. speed in mi/h to ft/s
c. area in km² to mi²
d. area in km² to cm²
e. mass/area of aluminum foil in mg/cm² to g/m²
f. number of gas molecules per unit volume from /ft³ to /m³
g. number of bacteria per unit area on a microscope slide from /in² to /mm²

Answer:

13.

Use the relationship between temperatures in Celsius and Fahrenheit to calculate the temperature at which
a. the numerical value is the same on both scales.
b. the Fahrenheit number is exactly twice the Celsius number.

Answer:

14.

In an average year the American chemical industry produces more than 9.5 million metric tons of sodium carbonate. Over half of this is used in the manufacture of glass while another third is used in the production of detergents and other chemicals. How many pounds of sodium carbonate are produced annually?

A.	2.1 × 10¹⁰ lb

B.	4.3 × 10⁹ lb

C.	1.1 × 10⁷ lb

D.	2.2 × 10⁶ lb

E.	2.1 × 10⁴lb

15.

The average distance between the Earth and the Moon is 240,000 miles. Express this distance in kilometers.

A.	6.1 × 10⁵km

B.	5.3 × 10⁵km

C.	3.9 × l0⁵km

D.	1.5 × 10⁵km

E.	9.4 × 10⁴km

16.

Zinc acetate is used in preserving wood and in manufacturing glazes for porcelain. What is its formula?

ZnAc₂

ZnCH₃COO

C.	Zn(CH₃COO)₂

Zn₂CH₃COO

E.	ZnCH₃COCH₃

17.

Which one of the following statements about atoms and subatomic particles is correct?

A.	Rutherford discovered the atomic nucleus by bombarding gold foil with electrons.

B.	The proton and the neutron have identical masses.

C.	The neutron's mass is equal to that of a proton plus an electron.

D.	A neutral atom contains equal numbers of protons and electrons.

E.	An atomic nucleus contains equal numbers of protons and neutrons.

18.

Millikan's oil-drop experiment

A.	established the charge on an electron.

B.	showed that all oil drops carried the same charge.

C.	provided support for the nuclear model of the atom.

D.	suggested that some oil drops carried fractional numbers of electrons.

E.	suggested the presence of a neutral particle in the atom.

19.

Which one of the following combinations of names and formulas of ions is incorrect?

O^2-oxide

B.	Cd²⁺cadmium

C.	ClO₃- chlorate

D.	HCO₃- hydrogen carbonate

E.	NO₂- nitrate

20.

Atoms X, Y, Z, and R have the following nuclear compositions:

Which two are isotopes?

X & Y

X & R

Y & R

Z & R

X & Z

21.

Calcium hydroxide is used in mortar, plaster and cement. What is its formula?

CaOH

CaOH₂

Ca₂OH

Ca(OH)₂

CaHO₂

22.

Sodium chromate is used to protect iron from corrosion and rusting. Determine its molecular mass.

A.	261.97 amu

B.	238.98 amu

C.	161.97 amu

D.	138.98 amu

74.99 amu

23.

Which one of the following formulas of ionic compounds is the least likely to be correct?

NH₄Cl

Ba(OH)₂

Na₂SO₄

Ca₂NO₃

Cu(CN)₂

24.

Bromine is the only nonmetal that is a liquid at room temperature. Consider the isotope bromine-81, Select the combination which lists the correct atomic number, neutron number, and mass number, respectively.

A.	35, 46, 81

B.	35, 81, 46

C.	81, 46, 35

D.	46, 81, 35

E.	35, 81, 116

25.

Which of the following is a metal?

A.	nitrogen, N, Z = 7

B.	phosphorus, P, Z = 15

C.	arsenic, Z = 33

D.	thallium, Tl, Z = 81

E.	silicon, Si, Z = 14

26.

What is the name of BBr₃?

A.	boron bromide

B.	boric bromide

C.	boron tribromide

D.	tribromoboride

E.	bromine triboride

27.

Diiodine pentaoxide is used as an oxidizing agent that converts carbon monoxide to carbon dioxide. What is its chemical formula?

I₂O₅

IO₅

2IO₅

I₅O₂

(IO₅)₂

28.

What is the name of the acid formed when H₂S gas is dissolved in water?

A.	sulfuric acid

B.	sulfurous acid

C.	hydrosulfuric acid

D.	hydrosulfurous acid

E.	sulfidic acid

29.

The mass of a neutron is equal to the mass of a proton plus the mass of an electron.

True

False

30.

Determine the molecular mass of iron (III) bromide hexahydrate, a substance used as a catalyst in organic reactions.

A.	403.65 amu

B.	355.54 amu

C.	317.61 amu

D.	313.57 amu

E.	295.56 amu

31.

Structural isomers have the same molecular formula but different structural formulas.

True

False

32.

Balance the following equation:
UO₂(s) + HF(l) → UF₄(s) + H₂O(l)

A.	UO₂(s) + 2HF(l) → UF₄(s) + H₂O(l)

B.	UO₂(s) + 4HF(l) → UF₄(s) + 2H₂O(l)

C.	UO₂(s) + H₄F₄(l) → UF₄(s) + H₄O₂(l)

D.	UO₂(s) + 4HF(l) → UF₄(s) + 4H₂O(l)

E.	UO₂(s) + 8HF(l) → 2UF₄(s) + 4H₂O(l)

33.

Ammonia, NH₃, is produced industrially from nitrogen and hydrogen as follows:
N₂(g) + 3H₂(g) → 2NH₃(g)
What mass, of which starting material, will remain when 30.0 g of N₂ and 10.0 g of H₂react until the limiting reagent is completely consumed?

Answer:

34.

Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles).
SO₂(g) + 2Cl₂(g) → SOCl₂(g) + Cl₂O(g)
If 0.400 mol of Cl₂reacts with excess SO₂, how many moles of Cl₂O are formed?

0.800 mol

0.400 mol

0.200 mol

0.100 mol

E.	0.0500 mol

35.

How many grams of sodium fluoride (used in water fluoridation and manufacture of insecticides) are needed to form 485 g of sulfur tetrafluoride?
3SCl₂(l) + 4NaF(s) → SF₄(g) + S₂Cl₂(l) + 4NaCl(s)

1940 g

1510 g

754 g

205 g

51.3 g

36.

Phosphorus pentachloride, PCl₅, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of PCl₅.

5.38 mol

3.55 mol

0.583 mol

0.282 mol

0.186 mo1

37.

a. Balance the following equation for the combustion of butane, a hydrocarbon used in gas lighters:
C₄H₁₀(g) + O₂(g) → CO₂(g) + H₂O(l)

Answer:

38.

One mole of methane (CH₄) contains approximately 3 × 10²⁴ atoms.

True

False

39.

Consider the balanced equation:
Al₂S₃(s) + 6H₂O(l) → 2Al(OH)₃(s) + 3H₂S(g)
If 15.0g of aluminum sulfide and 10.0g of water are allowed to react as above, and assuming a complete reaction
a. by calculation, find out which is the limiting reagent.
b. calculate the maximum mass of H₂S which can be formed from these reagents.
c. calculate the mass of excess reagent remaining after the reaction is complete.

Answer:

40.

Sodium chlorate is used as an oxidizer in the manufacture of dyes, explosives and matches. Calculate the mass of solute needed to prepare 1.575 L of 0.00250 M NaClO₃(M = 106.45 g/mol).

419 g

169 g

0.419 g

0.169 g

0.00394 g

41.

What will be the final volume of a solution prepared by diluting 25 mL of 8.25 M sodium hydroxide to a concentration of 2.40 M?

330 mL

2l0 mL

86 mL

60 mL

7.3 mL

42.

The formula CH₃O_0.5 is an example of an empirical formula.

True

False

43.

A compound consisting of C, H and O only, has a molar mass of 331.5 g/mol. Combustion of 0.1000 g of this compound caused a 0.2921 g increase in the mass of the CO₂ absorber and a 0.0951 g increase in the mass of the H₂O absorber. What is the empirical formula of the compound?

Answer:

44.

Propane, C₃H₈, is commonly provided as a bottled gas for use as a fuel. In 0.200 mol of propane
a. what is the mass of propane?
b. what mass of carbon is present?
c. how many molecules of C₃H₈ are present?
d. how many hydrogen atoms are present?

Answer:

45.

Calculate the molar mass of Ca(BO₂)₂·6H₂O.

A.	273.87 g/mol

B.	233.79 g/mol

C.	183.79 g/mol

D.	174.89 g/mol

E.	143.71 g/mol

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