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WorksheetsPre-AP Chemistry SE Mock Exam--version 1
Total questions: 40
Worksheet time: 2hrs 0mins
Compared to the charge and mass of an electron, a proton has
the same charge and smaller mass
the same charge and the same mass
an opposite charge and a greater mass
an opposite charge and the same mass
Consider the Bohr Model of Phosphorous below. Which statement is false?
The electrostatic potential energy of ALL electrons is negative.
The electrons with the least potential energy are closest to the nucleus.
Energy is released when the electron is ejected from the atom.
When an electron is very far away from the atom, the electrostatic potential energy is 0.
Which best represents the isotope shown above?
28 protons, 26 electrons, and 34 neutrons
26 protons, 26 electrons, and 36 neutrons
28 protons, 26 electrons, and 26 neutrons
26 protons, 24 electrons, and 36 neutrons
Chemists can identify the composition of some unknown salts by conducting a flame test. When potassium salts are heated in a flame, a purple color is observed. This is due to the movement of electrons between energy levels. What is the electron configuration of a potassium atom at ground state?
1s22s22p63s23p64d1
1s22s22p63s23p63d1
1s22s22d63s23d64s1
1s22s22p63s23p64s1
In a 3.7-gram sample, there are _________________ atoms of gold (Au).
1.1 x 1022 atoms of gold
3.2 x 1025 atoms of gold
4.4 x 1026 atoms of gold
3.1 x 10-26 atoms of gold
Which total mass is the largest?
The mass of 2 electrons
The mass of 2 neutrons
The mass of 1 electron plus the mass of 1 proton
The mass of 1 neutron plus the mass of 1 electron
Which of the following has the smallest ionic radius?
P3-
K1+
Sc3+
Ar
According to the mass spectrum above, the average mass of tin in this is sample is
219.76 amu
118.79 amu
118.00 amu
61.67 amu
What information do the experimental results above reveal about the nucleus of the gold atom?
The nucleus contains less than half the mass of the atom.
The nucleus is small and is the densest part of the atom.
The nucleus contains small positive and negative particles.
The nucleus is large and occupies most of the atom’s space.
Which of the following does not match the others?
1s22s22p5
Consider the electron configuration 1s22s22p63s23p63d84s2. Which of the following statements is false?
There are 16 electrons on the third energy level.
This atom has 2 valence electrons
There are 4 energy levels in the atom.
The next electron to be added will be in sublevel 4p
Which is true about the 3p electrons in sulfur?
They travel in a figure 8 orbit
They are located much closer to the nucleus than the 2p electrons
They are the highest energy electrons in a sulfur atom
They shield the 2s electrons from the full charge of the nucleus
Consider the table below. What is the relative abundance of isotope A?
0.100
0.325
0.575
0.650
How many grams of copper are in 4.6 moles?
0.072 grams
13.8 grams
134.2 grams
292 grams
As a distant star moves away from Earth, the light given off by the star has a measurably lower frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes lower?
The wavelength becomes longer, and the energy decreases
The wavelength becomes shorter, and the energy decreases.
The wavelength becomes longer, and energy increases
The wavelength becomes shorter, and the energy increases
What is the molecular geometry of iodine trifluoride, IF3?
Trigonal planar
T-shaped
Trigonal pyramidal
Tetrahedral
The correct Lewis structure for BF3 would have exactly:
1 double bond
2 double bonds
No double bonds
1 triple bond
Nitrogen has a greater first ionization energy than phosphorus. What is the best evidence to support this observation?
Nitrogen has a greater effective nuclear charge.
A nitrogen atom is larger than a phosphorus atom.
The electron ionized from nitrogen is in a lower energy level closer to the nucleus.
The electron ionized from nitrogen is from a core energy level.
Caustic soda is 20 M NaOH and is diluted for household use. What is the household concentration if 10 mL of the concentrated solution is diluted to 500 mL?
0.4 M NaOH
400 M NaOH
4 M NaOH
20 M NaOH
A sample of 0.0255 mol potassium hydroxide (KOH) was dissolved in water to yield 10.0 mL of solution. What is the molarity of the solution?
0.4 M
2.55 M
0.25 M
4 M
The chart below shows the relationship between ionization energy and the increase in atomic number. The letter on the chart for the noble gases (Group 18) is most likely:
W
X
Y
Z
Valence electrons in an atom of phosphorus are closer to the nucleus than the valence electrons of aluminum because:
P has a greater effective nuclear charge and a greater shielding than Al
P has a greater effective nuclear charge with the same shielding as Al
P has the same effective nuclear charge with greater shielding than Al
P has the same effective nuclear charge and the same shielding as Al
A chemist walks into his laboratory and finds that his assistant has reorganized his chemical cabinet to more closely relate to the trends on the periodic table. Not realizing this, he takes several chemical elements out and puts them back incorrectly. Using your knowledge of the periodic table, select the shelves that have misplaced chemical elements:
I. Most reactive shelf: Lithium, Potassium, Rubidium, Francium
II. Transitional metal shelf: Nickel, Copper, Zinc, Argon
III. Highly electronegative elements shelf: Fluorine, Sulfur, Selenium, Strontium
IV. Un-reactive shelf: Krypton, Neon, Radon, Helium
. I and II only
II and III only
. II, III, and IV only
I, II, III, and IV
According to the solubility curve, which of the following ionic compounds would be considered unsaturated when 80 grams of solute is dissolved in 100 grams of water at 70°C?
NH4Cl
KCl
Ce2(SO4)3
KNO3
What combination of two elements would most likely form an ionic solid?
V and W
X and Z
V and Y
X and Y
Based on the Lewis dot structures for these elements, which of the following is the correct formula for a bond between X and V?
VX
V2X3
V3X
VX3
According to the picture below, which statement is false?
Ultraviolet rays have a higher frequency than microwaves.
As wavelength gets shorter, the energy increases.
Red light (wavelength = 700nm) has less energy than blue light (wavelength = 500nm).
Radio waves have the shortest wavelength.
Which of the following Lewis dot diagrams is incorrect?
Which of the following particles has a central atom that does NOT obey the octet rule in its most stable form:
HCN
H2O
BeH2
PCl3
A sample of element X contains 90% X-35, 8.0% X-37, and 2.0% X-38 atoms. The average atomic mass will be closest to which value?
35
36
37
38
What is the molecular geometry of carbon dioxide, CO2?
Bent
Tetrahedral
Trigonal pyramidal
Linear
Which term refers to how strongly an atom of an element attracts electrons in a chemical bond with another atom?
Ionization energy
Atomic radius
Melting point
Electronegativity
Which of the following would have a trigonal pyramidal geometry?
NO2 -1
O3
H2O
PCl3
Calculate the molarity of a solution in which 360. grams of glucose, C6H12O6, are dissolved in enough water to make 250. mL of solution.
1.0 M
2.0 M
4.0 M
8.0 M
All of the following are ways to increase the rate of dissolving sugar except…
Increasing the mass of sugar
Crushing the sugar into a fine powder
Stirring with a spoon
Increasing the temperature of the water
Consider what you know about the polarity of water molecules. Which of the following molecules is NOT soluble in water?
Why does heating increase the speed at which a solid dissolves?
Heating increases kinetic energy of particles, resulting in more effective collisions between solvent and solute.
Heating causes particles to decompose, resulting in smaller solute particles that are more easily dissolved in the solvent.
Heating increases the ratio of solvent to solute particles, making it easier for solute particles to be distributed among solvent particles.
Heating does not affect the speed at which a solid dissolves.
The solution in Beaker A conducts electricity, whereas the solution in Beaker B does not conduct electricity. Based on this data, which answer choice lists possible options for the solutes in each beaker?
Beaker A – NaNO3; Beaker B – C2H5OH
Beaker A – NaCl; Beaker B – AgNO3
Beaker A – C2H5OH; Beaker B – NaCl
Beaker A – Pb(NO3)2; Beaker B – KNO3
How many grams are in 2.3 x 1024 formula units of KNO3?
38.6 grams
102.3 grams
140 grams
386 grams
Which statement describes the general trends in electronegativity and first ionization energy as the elements in Period 3 are considered in order from Na to Cl?
Electronegativity increases, and first ionization energy decreases
Electronegativity decreases, and first ionization energy decreases
Electronegativity and first ionization energy both increase
Electronegativity and first ionization energy both decrease
