1.
What is the number of electrons in a completely filled second shell of an atom?
Correct Answer
D. 8
Explanation
The maximum number in the second orbital is 8...check out the electron configurations.
2.
What is the number of electrons in an atom that has 3 protons and 4 neutrons?
Correct Answer
C. 3
Explanation
Protons equal electrons.
3.
As a result of the gold foil experiment, it was concluded that an atom
Correct Answer
B. Contains a small, dense nucleus
Explanation
Gold foil experiment showed us that the atom contains a small, dense nucleus...it also showed us that the atom was mostly empty space.
4.
Which statement describes the distribution of charge in an atom?
Correct Answer
C. A positively charged nucleus is surrounded by one or more negatively charged electrons.
Explanation
POSITIVELY charged nucleus (protons are positive and neutrons are neutral) surrounded by NEGATIVELY charged electrons.
5.
Which atom in the ground state has an outermost electron with the most energy?
Correct Answer
A. Cs
Explanation
Cs has the most orbitals...the outer orbitals have more energy.
6.
Which particle has the least mass?
Correct Answer
B. Beta particle
Explanation
Check out Table O for the comparison. The top number is the mass number.
7.
The elements in Group 2 are classified as
Correct Answer
A. Metals
Explanation
Metals make up the majority of the elements. All elements to the left of the "staircase" are metals. Metals lose electrons, making POSITIVE ions.
8.
Which list includes elements with the most similar chemical properties?
Correct Answer
C. O, S, Se
Explanation
Oxygen, Sulfur, and Selenium are all in the same group. They have the same number of valence electrons, therefore similar chemical properties.
9.
Correct Answer
C. Both mass number and atomic number
Explanation
The top number is the mass number (protons + neutrons) and the bottom number is the atomic number (protons)
10.
Which pair represents two forms of an element in the same phase at STP but with different structures and different properties?
Correct Answer
B. O2(g) and O3(g)
Explanation
Phase means SOLID, LIQUID, or GAS. The oxygen and ozone are two forms of oxygen in the same phase.
11.
The elements on the Periodic Table are arranged in order of increasing
Correct Answer
B. Atomic number
Explanation
The Periodic Table is arranged by atomic number, or number of protons. While it may seem that it is also arranged according to atomic mass, it is not the case. The atomic mass skips around a bit in the transition elements (the skinny section where Fe and Cu are located).
12.
What is the IUPAC name for the compound ZnO?
Correct Answer
A. Zinc oxide
Explanation
For ionic compounds, the metal is listed according to the atomic name and the nonmetal's ending is changed to end in -ide. OXygen becomes OXide.
13.
Which atom attains a stable valence electron configuration by bonding with another atom?
Correct Answer
C. Hydrogen
Explanation
Process of elimination. Three of these are noble gases. Hydrogen needs one more electron for its full valence.
14.
An ionic bond can be formed when one or more electrons are
Correct Answer
D. Transferred from the valence shell of one atom to the valence shell of another atom
Explanation
Ionic bonds involve the transfer of electrons. Electrons are not found in the nucleus.
15.
Which sample of CO2 has a definite shape and a definite volume?
Correct Answer
D. CO2 (s)
Explanation
Solids have a definite shape and definite volume...Remember? It was the dry ice lab.
16.
What occurs in order to break the bond in a Cl2 molecule?
Correct Answer
A. Energy is absorbed.
Explanation
To break something requires force, so the energy is absorbed.
17.
A sealed, rigid 1.0-liter cylinder contains He gas at STP. An identical sealed cylinder contains Ne gas at STP. These two cylinders contain the same number of
Correct Answer
A. Atoms
Explanation
Process of elimination, but any two equally-sized containers have the same number of particles of gas present at the same temperature and pressure.
18.
Which statement describes a chemical change?
Correct Answer
D. Glucose (C6H12O6) and oxygen produce CO2 and H2O.
Explanation
Three of them are physical changes (either phase change or shape change). A chemical reaction indicates a chemical change.
19.
Which statement describes the particles of an ideal gas according to the kinetic molecular theory?
Correct Answer
B. The gas particles are in random, constant, straight-line motion.
Explanation
Ideal gases have NO ATTRACTION. They have a RANDOM, STRAIGHT-LINE MOTION. They also have GREAT DISTANCES between them.
20.
Which sample of matter is classified as a substance?
Correct Answer
B. Ammonia
Explanation
Three of these are mixtures (air is a mixture of gases, milk has water and proteins, and seawater has salt and water).
Ammonia is ONLY NH3.
21.
Which element has the lowest electronegativity value?
Correct Answer
B. Fr
Explanation
Electronegativity is how strongly an element wants an electron. Fluorine has the highest and Fr (on the opposite corner of the Periodic Table) has the lowest value. Look in Table S.
22.
At standard pressure, CH4 boils at 112 K and H2O boils at 373 K. What accounts for the higher boiling point of H2O at standard pressure?
Correct Answer
C. Hydrogen bonding
Explanation
Hydrogen bonding occurs when a polar molecule unevenly shares electrons with hydrogen atoms...the hydrogen atoms tend to have a positive charge and are attracted to the negatively charged atoms in the same molecule.
23.
A mixture of sand and table salt can be separated by filtration because the substances in the mixture differ in
Correct Answer
D. Solubility in water
Explanation
Sand doesn't dissolve in water. Filtration separates solids from liquids that are not soluble.
24.
Systems in nature tend to undergo changes toward
Correct Answer
B. Lower energy and higher entropy
Explanation
Lower energy (heat is the lowest form of energy) and higher entropy...entropy is randomness.
25.
In the wave-mechanical model of the atom, an orbital is the most probable location of
Correct Answer
D. An electron
Explanation
ORBITAL = ELECTRON...I hope you didn't get this wrong.
26.
Functional groups are used to classify
Correct Answer
A. Organic compounds
Explanation
organic compounds involve functional groups...If you get confused, look at Table R.
27.
Which class of compounds contains at least one element from Group 17 of the Periodic Table?
Correct Answer
D. Halide
Explanation
Halides include FLUORINE, CHLORINE, and BROMINE.
28.
In a propanal molecule, an oxygen atom is bonded with a carbon atom. What is the total number of pairs of electrons shared between these atoms?
Correct Answer
B. 2
Explanation
The -CO bond is a double bond, and four electrons total are shared (two pairs).
29.
When a voltaic cell operates, ions move through the
Correct Answer
C. Salt bridge
Explanation
Ions travel through the salt bridge. The electrons travel from the anode to the cathode through the wire.
30.
When dissolved in water, an Arrhenius base yields
Correct Answer
C. Hydroxide ions
Explanation
Arrhenius bases yield ONLY hydroxide as the negative ions.
31.
What is the total number of valence electrons in a germanium atom in the ground state?
Correct Answer
D. 4
Explanation
Look at the electron configuration. The Ge atom has the last number of 4 (valence electron).
32.
Which element is paired with an excited-state electron configuration for an atom of the element?
Correct Answer
C. K: 2-6-8-3
Explanation
K is the only one that has an incomplete inner shell.
33.
Given the balanced equations representing two chemical reactions:
Cl2 + 2NaBr → 2NaCl + Br2
2NaCl → 2Na + Cl2
Which types of chemical reactions are represented by these equations?
Correct Answer
A. Single replacement and decomposition
Explanation
1st reaction: single replacement (element and compound switch partners)
2nd reaction: decomposition (one breaks down into two)
34.
An ion that consists of 7 protons, 6 neutrons, and 10 electrons has a net charge of
Correct Answer
B. 3−
Explanation
7 protons (+7)
10 electrons (-10)
The difference is -3.
35.
Which Lewis electron-dot diagram represents a molecule having a nonpolar covalent bond?
Correct Answer
A.
Explanation
Nonpolar bond means there is no difference in electronegativity. Cl-Cl bonds have no difference, so there is no polarity in the bond.
36.
Which quantity is equal to 50 kilojoules?
Correct Answer
D. 50 000 J
Explanation
50 kJ is the same as 50 x 1000 kJ
37.
Which compound is formed from its elements by an exothermic reaction at 298 K and 101.3 kPa?
Correct Answer
C. H2O (g)
Explanation
There's only one. You are looking into the PRODUCTS in Table I.
38.
At which temperature is the vapor pressure of ethanol equal to 80. kPa?
Correct Answer
B. 73°C
Explanation
Table H:
On the Y axis, locate 80 kPa and follow it to the right until you reach the graph for ethanol. Look on the X axis to determine the temperature, 73.
39.
At 25°C, gas in a rigid cylinder with a movable piston has a volume of 145 mL and a pressure of 125 kPa. Then the gas is compressed to a volume of 80. mL. What is the new pressure of the gas if the temperature is held at 25°C?
Correct Answer
D. 230 kPa
Explanation
P1: 125 kPa
V1: 145 mL
T1: 298 K (25 + 273)
P2: unknown
V2: 80 mL
T2: 298 K
40.
A 2400.-gram sample of an aqueous solution contains 0.012 gram of NH3. What is the concentration of NH3 in the solution, expressed as parts per million?
Correct Answer
A. 5.0 ppm
Explanation
grams of solute: 0.012 g NH3
grams of solution: 2400
41.
Which equation represents a change that results in an increase in disorder?
Correct Answer
A. I2 (s) → I2 (g)
Explanation
3 of go "down" a phase and only one goes "up" a phase. Gases show the most entropy (disorder).
42.
A solution consists of 0.50 mole of CaCl2 dissolved in 100. grams of H2O at 25°C. Compared to the boiling point and freezing point of 100. grams of H2O at standard pressure, the solution at standard pressure has
Correct Answer
C. A higher boiling point and a lower freezing point
Explanation
The ions interfere with the formation of ice as well affect the boiling point. They lower freezing point and raise the boiling points.
43.
Given the balanced ionic equation representing a reaction:
Which half-reaction represents the reduction that occurs?
Correct Answer
D.
Explanation
Copper is lowering in oxidation, so it undergoes REDUCTION.
44.
Given the equation and potential energy diagram representing a reaction:
If each interval on the axis labeled “Potential Energy (kJ/mol)” represents 10. kJ/mol, what is the heat of reaction?
Correct Answer
D. +40. kJ/mol
Explanation
Activation energy is the force it takes to "ROLL THE BALL UP THE HILL."
45.
Some solid KNO3 remains at the bottom of a stoppered flask containing a saturated KNO3(aq) solution at 22°C. Which statement explains why the contents of the flask are at equilibrium?
Correct Answer
A. The rate of dissolving is equal to the rate of crystallization.
Explanation
As some particles dissolve, others come out of solution and crystallize.
46.
Which formula represents the product of the addition reaction between ethene and chlorine, Cl2?
Correct Answer
B.
Explanation
The CH2ClCH3 (chloroethane) is the result of an organic substitution reaction. When you have an addition reaction, something is ADDED to what you already have.
47.
Based on Reference Table J, which two reactants react spontaneously?
Correct Answer
A. Mg(s) + ZnCl2(aq)
Explanation
Magnesium is higher than Zinc. It will oxidize.
48.
When the pH value of a solution is changed from 2 to 1, the concentration of hydronium ions
Correct Answer
D. Increases by a factor of 10
Explanation
The pH is decreasing, which means the H+ increases 10 times.
49.
Given the balanced equation representing a nuclear reaction:
Which phrase identifies and describes this reaction?
Correct Answer
C. Fusion, mass converted to energy
Explanation
FUSION because two elements become one. Some mass is converted to energy.
50.
Given the equation representing a reversible reaction:
According to one acid-base theory, the reactant that donates an H+ ion in the forward reaction is
Correct Answer
B. H2O(l)
Explanation
The water got rid of a proton (H+) and gave it to ammonia (NH3) to form NH4+