AP Chemistry Unit 1 Review Questions

How many significant figures are there in 0.00723 m?
1. 6
2. 5
3. 4
4. 3
5. 2
Express 0.00723 m in scientific notation.
1. 723 x 10^-5 m
2. 72.3 x 10^-4 m
3. 7.23 x 10^-3 m
4. 7.23 x 10³ m
5. 723 x 10⁵ m
After doing a calculation the display shows the number 3760.289 on the calculator. If the answer is supposed to have three significant figures, the correct way to display the answer would be:
1. 376
2. 3760.
3. 3.76 x 10³
4. 3.76 x 10²
5. 376 x 10¹
Using the rules for significant figures, calculate the following: (8.790 - 13)/3.90
1. -1.03
2. -1
3. -1.08
4. -1.1
5. --1.079
One meter contains how many micrometers?
1. 1 x 10⁶
2. 1 x 10^-6
3. 1 x 10³
4. 1 x 10⁹
5. 1 x 10^-9
The melting point of the element palladium (atomic #46) is 1552°C. What is the melting point of palladium on the Fahrenheit scale?

(T_F = T_C x (9°F/5°C) + 32°F)
1. 524576°F
2. 1825°F
3. 3000°F
4. 2825.6°F
5. 2825°F
If the melting point of palladium is 1552°C, in what physical state does palladium exist at 2000°C?
1. solid
2. liquid
3. gas
4. a mixture of solid and liquid
5. not enough information to answer the question
Which of the following is an example of a pure substance?
1. pure water
2. granite
3. air
4. gun powder
5. none of these
All measurements in science involve a degree of:
1. precision
2. accuracy
3. uncertainty
4. disorder
5. conversion
A solid sample of a metal is submerged in a large graduated cylinder. The water level in the graduate was 55.25 mL and the final level was 61.00 mL. If the mass of the object was determined to be 23.795 g, what is the density of the metal?
1. 4.138 g/mL
2. 4.13 g/cm³
3. 4.14 g/cm³
4. 4.1 g/cm³
5. 4 g/mL
Convert 0.0023 mm to meters.
1. 2.3 m
2. 2.3 x 10³ m
3. 2.3 x 10⁶ m
4. 0.000023 m
5. 2.3 x 10^-6 m
Benzene is a nonpolar molecule, liquid at room temperature, with a density of 0.8787 g/cm³. When mixed with water, benzene will:
1. blend with the water until the mixture appears homogeneous.
2. float on top of the water
3. sink to the bottom
4. solidify
5. vaporize
You measure the mass of one object on a scale on which the "slider" has marks for each consecutive gram. You measure the mass of a second object on a digital scale the displays mass in grams to three decimal places. When you add the masses of the two objects, to what decimal place can you record your final answer?
1. 0.01 g
2. 0.1 g
3. 1 g
4. 10 g
5. none of these
The difference in mass between a high school boy's discus and a high school girl's discus is 0.616 kilograms. Convert this difference to lbs.

(1 kilogram = 2.205 lb)
1. 1.36 lb
2. 1.358 lb
3. 0.279 lb
4. 0.2794 lb
5. 1.4 lb
Which of the following equalities is incorrect?
1. 1.35 micrometers = 1.35 x 10³ millimeters
2. 0.079 mL = 0.079 cm³
3. 7.43 x 10^-2 nanoliters = 7.43 x 10^-8 milliliters
4. 3.5 kilograms = 3.5 x 10⁶ milligrams
5. 1.89 x 10⁴ deciliters = 1.89 x 10³ liters
You are given five pieces of pure aluminum, all of different sizes. You measure both the mass and volume of each piece, and plot mass vs. volume on a graph. Assuming your results are accurate, the plot on your graph is:
1. parabolic
2. hyperbolic
3. a single point
4. a straight line
5. circular
The density of mercury is 13.5939 g/cm³. Calculate the mass in kilograms of a drum full of mercury with the following dimensions: height = 1.100 meters, diameter = 0.492 meters. Assume pi has a value of 3.14.
1. 2.84 x 10⁶ kg
2. 2.09 x 10² kg
3. 2.84 x 10³ kg
4. 2.84 kg
5. 2.84 x 10^-3
Substances with constant composition that cannot be broken down into simpler substances by chemical processes are:
1. elements
2. compounds
3. mixtures
4. solutions
5. salts
Which of the following is not a fundamental SI unit?
1. gram
2. candela
3. mole
4. Kelvin
5. meter
The freezing of water is:
1. a chemical change because it involves a change in energy
2. a physical change because there is no color change
3. a chemical change because ice is less dense than liquid water
4. a physical change because both ice and liquid water consist solely of H₂O
5. a chemical change because it does not take place spontaneously
By knowing the number of electrons in a neutral atom, you should also be able to determine
1. the number of neutrons in the neutral atom
2. the number of protons in the neutral atom
3. the atomic number of the neutral atom
4. the mass of the neutral atom
5. two of these
The apparatus pictured here helped to determine:
1. the existence of electrons
2. that atoms are mostly empty space
3. that energy travels at the speed of light
4. that electrons have mass
5. that mass and energy are related by E=mc²
Which of the following arrangements represent ions?

1) 12 protons, 12 neutrons, 11 electrons
2) 12 protons, 11 neutrons, 12 electrons
3) 11 protons, 12 neutrons, 12 electrons
4) 11 protons, 12 neutrons, 11 electrons
5) 12 protons, 12 neutrons, 12 electrons
1. 1 and 2
2. 1, 3, and 4
3. 1 and 3
4. 2 and 3
5. all of these are ions
Which of the following arrangements represent different isotopes of the same element?

1) 12 protons, 11 neutrons, 12 electrons
2) 11 protons, 12 neutrons, 11 electrons
3) 10 protons, 12 neutrons, 12 electrons
4) 11 protons, 12 neutrons, 10 electrons
5) 12 protons, 12 neutrons, 12 electrons
1. 1 and 5
2. 2 and 4
3. 2, 3, 4 and 5
4. all of these qualify
5. None of these qualify
The average mass of a magnesium atom is 24.31. If you were able to select and measure a single atom of magnesium, the chance that you would select an atom of mass 24.31 is about:
1. 0%
2. 0.31%
3. 24.31%
4. greater than 50%
5. 100%
How many oxygen atoms are there in one formula unit of Al₂(SO₄)₃?
1. 3
2. 4
3. 7
4. 12
5. 24
Which of the following is named incorrectly?
1. H₂CO₂ : carbonous acid
2. HClO₂ : chlorous acid
3. H₂SO₄ : sulfuric acid
4. HClO : hydrochlorous acid
5. H₃PO₃ : phosphorous acid
The name for the compound NaHSO₄ is:
1. sodium hydrogen sulfate
2. sodium persulfate
3. sodium bisulfate
4. two of these are correct
5. none of these is correct
Which of following is not true of the carbon-14 atom?
1. It has six protons
2. It has an average mass of 12.011 amu.
3. It has six electrons
4. It has eight neutrons
5. It is the less common than carbon-12
Of the following elements, the one that forms cations with varying positive charges is:
1. iron, Fe
2. sodium, Na
3. aluminum, Al
4. strontium, Sr
5. nitrogen, N
The correct name for MgO₂ is:
1. magnesium(II) oxide
2. magnesium(IV) oxide
3. magnesium peroxide
4. magnesium oxide
5. magnesium(IV) peroxide
A particle with 15 protons and 18 electrons would be symbolized as:
1. Ar
2. Ar^3-
3. P^3-
4. P³⁺
5. Ar³⁺
Which of the following statements is incorrect?:
1. metals generally form cations
2. nonmetals are generally poor conductors of electricity
3. metals are malleable
4. nonmetals are generally brittle
5. metalloids are metals with some nonmetallic characteristics
Which of these is the correct number of particles in the nuclide shown above?
1. 34 protons, 79 neutrons, 2 electrons
2. 34 protons, 45 neutrons, 32 electrons
3. 34 protons, 45 neutrons, 2 electrons
4. 34 protons, 45 neutrons, 36 electrons
5. 34 protons, 113 neutrons, 36 electrons
Which of the above have equal numbers of neutrons?
1. I, II and III
2. II and III
3. I and V
4. I and IV
5. II, III and IV
Ions are formed in chemical reactions by:
1. Gaining electrons
2. Losing electrons
3. Gaining protons
4. Losing protons
5. Gaining neutrons
6. Losing neutrons
The number of errors contained in the table below is:

Nuclide protons neutrons electrons mass
sodium-23 11 12 11 23
Cobalt-59 27 22 27 59
Tungsten-184 74 110 184 184
fluorine-19 10 9 10 19
1. one
2. two
3. three
4. four
5. five
The element hafnium (Hf) has five stable isotopes. The correct number of nuclear particles in an atom of hafnium-178 is:
1. 72 protons, 178 neutrons
2. 72 protons, 72 electrons
3. 106 protons, 72 neutrons
4. 72 protons, 106 neutrons
5. 72 protons, 106 neutrons, 72 electrons
J.J. Thomson's model of the atom can be summarized with the visual image of:
1. planets orbiting the sun
2. plum pudding
3. bees around a hive
4. a small central nucleus and an electron cloud
5. none of the above
A particle X contains 10 electrons, seven neutrons and has a net charge of 3-. The particle is:
1. a nitride ion
2. obviously polyatomic
3. an oxide ion
4. a neon ion
5. none of these are correct
Butane, CH₃-CH₂-CH₂-CH₃, is a hydrocarbon fuel used in lighters. How many moles of molecules are there in a 350. gram sample of butane?
1. 6 mol
2. 6.02 mol
3. 0.170 mol
4. 20349 mol
5. 20300 mol
For which of the following compounds does 0.400 mol have a mass of 12.8 grams?
1. CH₄
2. CCl₄
3. CO₂
4. C₄H₁₀
5. CH₃OH
What is the molar mass of glucose, C₆H₁₂O₆?
1. 160.00 g
2. 180.18 g
3. 18 g
4. 12.01 g
5. 220.17 g
Methane, CH₄, and ethane, C₂H₆ are both hydrocarbons that exist as gases at room conditions. How many grams of ethane contain the same number of molecules as 6.00 g of methane?
1. 11.2 grams
2. .374 grams
3. 80.5 grams
4. 0.09 grams
5. 2896 grams
A substance with the formula AB has the composition by mass of 30% A and 70% B. What is the composition by mass of the compound A₂B?
1. 65% A, 35% B
2. 70% A, 30% B
3. 46% A, 54% B
4. 60% A, 40% B
5. 50% A, 50% B
How grams of oxygen are present in a 30.0 gram sample of potassium chlorate?
1. 36.8 grams
2. 7.83 grams
3. 3.83 grams
4. 150.45 grams
5. 11.8 grams
18.0 grams of carbon is burned in 55.0 grams of oxygen. How many grams of carbon dioxide are formed?
1. 151 grams CO₂
2. 75.6 grams CO₂
3. 66.0 grams CO₂
4. 44.01 grams CO₂
5. 12.01 grams CO₂
When the equation for the combustion of ethane, C₂H₆, is correctly balanced, the coefficient on oxygen is:
1. 1
2. 3
3. 5
4. 7
5. 9
Given the equation 3A + 4B → 2C + 3D, you react 5 moles of A with 7 moles of B. Which of the following statements is true?
1. A is the limiting reactant
2. B is the limiting reactant
3. A and B are in ideal stoichiometric proportions
4. A has a greater molar mass than B
5. B has a greater molar mass than A
A chemistry student decomposes a 78.0 gram sample of potassium chlorate, using manganese dioxide as a catalyst. Her effort yields 24.247 grams of oxygen. What is her percent yield?
1. 30.1%
2. 79.2%
3. 20.8%
4. 59.9%
5. The answer cannot be calculated from the information provided.
When 13.5 grams of methane (CH₄) burns in 40.0 grams of oxygen, how many grams of water are formed?
1. 30.3 grams H₂O
2. 24.0 grams H₂O
3. 18.0 grams H₂O
4. 112 grams H₂O
5. 22.5 grams H₂O
A mass of 21.5 grams of calcium hydroxide reacts with an excess of phosphoric acid. What mass of calcium phosphate could be recovered from solution?
1. 326 grams
2. 31.6 grams
3. 94.7 grams
4. 284 grams
5. 186 grams
A mass of 21.5 grams of calcium hydroxide reacts with an excess of phosphoric acid. How many atoms of oxygen are found in the water produced in the reaction?
1. 1.75 x 10²³ atoms
2. 3.49 x 10²³ atoms
3. 8.75 x 10²² atoms
4. 7.0 x 10²³ atoms
5. 1.05 x 10²⁴ atoms
A 5.15 gram sample of a hydrocarbon is burned in oxygen, producing 15.6 grams of carbon dioxide and 8.45 grams of water. Assuming an excess of oxygen, what is the empirical formula of the hydrocarbon?
1. CH₄
2. C₃H₈
3. C₅H₁₂
4. C₇H₁₆
5. C₉H₂₀
A sample of an alcohol is tested and found to contain 52% carbon, 35% oxygen, and 13% hydrogen by mass. Tests indicate that the molecular weight of the molecule is between 30 and 80. What is the molecular formula of the alcohol?
1. CH₃OH
2. C₂H₅OH
3. C₃H₇OH
4. C₄H₉OH
5. C₅H₁₁OH

Nuclide	protons	neutrons	electrons	mass
sodium-23	11	12	11	23
Cobalt-59	27	22	27	59
Tungsten-184	74	110	184	184
fluorine-19	10	9	10	19