Chem 110 Final Quiz and Exam Keys
What is the chemical formula for ammonium sulfate?
(NH₄)₂SO₄
What is the correct name for B₂O₃?
Diboron trioxide
What volume of 2.50 M NaOH (40.00 g/mol) contains 0.100 mole of NaOH? a. 0.250 L b. 40.0 mL c. 25.0 mL d. 0.250 mL e. 0.0400 mL
b. 40.0 mL
Which element forms an ionic compound with oxygen that has the formula XO? a. germanium b. aluminum c. lithium d. calcium e. potassium
d. calcium
Which of the following does not show a correct relationship between units? a. 1 x 10³g = 1 kg b. 1 x 10⁻³s = 1 ms c. 1 nm= 1 x 10⁻⁹m d. 1 GB= 1 x 10⁹B e. 1 x 10⁻6µl = 1L
e. 1 x 10⁻6µl = 1L
Which of the following types of electromagnetic radiation has the longest wavelength? a. gamma rays b. x-rays c. visible d. infrared e. radiowaves
e. radiowaves
You place 0.0500 g Mg(s) in a coffee cup calorimeter with 100.0mL 1.00M HCl. The temperature increases from 22.21C to 24.46C. The reaction that occurs is: Mg(s) + 2 HCl(aq) → H₂(g) + MgCl₂(aq) What is the enthalpy change for the reaction per mole of magnesium? The specific heat capacity of the reaction solution is 4.20 J/g-C and the density of the solution is 1.00 g/ml.
-482 kJ/mol
List as many properties of hydrogen atoms that are revealed in its emission spectrum from a discharge tube
-Hydrogen atoms can absorb energy from an electric discharge -When they later lose that energy it is emitted in the form of a photon seen here as specific colors of light. -Since only selected energies (colors) of light are emitted it must be the case that hydrogen atoms have quantized energy states.
A sample containing oxalic acid (H₂C₂O₄) is dissolved in water and titrated to an equivalence point with 34.47mL of 0.485 M NaOH. The balanced reaction is shown below. How many grams of oxalic acid are there in the sample? (FW H₂C₂O₄ 90.04g/mol)
.752g H₂C₂O₄
Carbon monoxide (28.01 g/mol) is used in refining iron(III) oxide (159.7 g/mol) to produce the metal. Assuming 100% yield, how many grams of Fe would be produced if 1.40 x 10² g CO and 8.00 x 10² g Fe₂O₃ were allowed to react? Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g)
186 g
Perform the following mathematical operation and express the result to the correct number of significant figures. Show your work. 2.526/3.1 + 0.470/0.623 + 80.705/0.4326
188.2
An 88.5g piece of iron whose temperature is 78.8 C is placed in a beaker containing 244 g water at18.8 C. What is the final temperature (Tf) when thermal equilibrium is reached? Assume no heat is lost to the container and its surroundings. (cwater = 4.184 J/g-C, cFe = 0.449 J/g-C)
21.0 C
When ammonium nitrate (NH₄NO₃)(s) is used in explosives, it decomposes to N₂(g), O₂(g), and H₂O(g). Write the balanced decomposition reaction equation with the lowest whole-number coefficients. Determine the standard enthalpy of reaction using standard enthalpies of formation:
2NH₄NO₃(s) → 2N₂(g) + 3O₂(g) + 4H₂O(g) -236 kJ
You are an engineer that is designing a switch that works via the photoelectric effect. The metal used requires 6.7 x 10⁻¹⁹ J/atom to eject electrons. Will the switch work with light of 540 nm or greater? Why or why not? (h = 6.6262 × 10⁻³⁴ J·s)
3.7×10⁻¹⁹, not enough energy
A food chemist determined the concentration of acetic acid in a sample of apple cider vinegar. The volume of 1.215 M NaOH required to titrate a 25.00 mL sample of the vinegar was 19.85 mL. The density of the sample was 1.01 g/mL. What are (a) the molar concentration and (b) the percent by mass of acetic acid in this vinegar? (CH₃COOH, 60.05 g/mol)
5.74%
Compute the molar concentration of Lithium Chloride (LiCl) when 61.5g of this compound are dissolved into 250.0 mL of solution.
5.80 M
The combustion of liquefied butane to form carbon dioxide and water vapor occurs according to the reaction below. What is the enthalpy change per mole of CO₂ produced? 2C₄H₁₀(l) + 13O₂(g) →4CO₂(g) + 5H₂)(l) ∆H=-2707.8 kJ
676.95 kJ
n-Heptane (C₇H₁₆, 100.20 g/mol) is an undesirable component of gasoline because it burns explosively and contributes to engine "knocking." Write the balanced combustion reaction of C₇H₁₆,. Calculate the number of grams of C₇H₁₆, that react if 225 g CO2 (44.01 g/mol) are produced.
73.1 g
For each of the following, indicate whether a physical or chemical change occurs. A. Solid table salt is obtained from the evaporation of seawater. B. Alcohol is boiled off from rum. C. Mercury vapor is generated by heating mercury(II) oxide. D. Oxygen is removed from an iron oxide containing Fe₂O₃. E. Gold metal is separated from river sand by panning.
A. Physical B. Physical C. Chemical D. Chemical E. Physical
The electron affinities of group 17 elements are all negative values, but the electron affinity values of group 18 noble gases are all positive. Explain why.
All group 18 neutral atom noble gases have a filled valence shell. An added electron would have go into the next higher principle quantum shell. This would substantially increase the energy of the atom giving rise to a positive electron affinity (corresponding to a very low electron affinity since high electron affinity has a large negative number). This is why the noble gases exist in nature as neutral atoms and not as ions like Chloride, Cl¹⁻
Which of the following bonds is considered to be ionic? Explain why. C—O, Ca—Cl, S—N, Si—O
Ca-Cl because Ca is on the left side of the periodic table and Cl is o the right. As a result, the electronegativity difference is so great that the Cl gets the full electron pair becoming an anion and Ca ends up as a cation
Identify the ions in CaHPO₄ and in MgCl₂. Write the name of the compounds and the name and formula for each component ion. CaHPO₄: _____ MgCl₂: _____
CaHPO₄: Calcium hydrogen phosphate, Ca²⁺ Calcium ion, HPO₄²⁻ hydrogen phosphate MgCl₂: Magnesium chloride, Mg²⁺ Magnesium ion, Cl¹⁻ Chloride
What is the correct name for CCl₄?
Carbon tetrachloride
What is the correct name for N₂O₄?
Dinitrogen tetroxide
Hydrogen isocyanide (HNC) and hydrogen cyanide (HCN) have the same elemental composition. Is one structure more stable than the other? Support your answer with the Lewis structures and formal charges assigned to each atom for these molecules.
HCN has all atoms with a formal charge of 0. This form is the most stable.
The mass and volume of Jupiter are 1.90 × 10²⁷kg and 1.43 × 10³⁰ cm³. Jupiter's mass is about 318 times greater than Earth's, and its volume is 1321 times greater. Calculate the approximate densities of Jupiter and of Earth.
Jupiter: 1.33 g/cm³, Earth: 5.54 g/cm³
What is the correct formula for an ionic compound that contains magnesium ions and nitrate ions (NO₃¹⁻)?
Mg(No₃)₂
Choose the following ions that have the same ground state electron configuration: S²⁻, N³⁻, Mg²⁺, Br⁻
N³⁻ and Mg²⁺
What 2- ion has the same ground state electron configuration as Neon?
S²⁻
Explain what property permits two electrons to exist in one orbital.
The Pauli Exclusion Principle says that no two electrons can have the same set of quantum numbers. The quantum number ms can have values of -1/2 or +1/2.
Write out the full ground state electronic configuration of Vanadium (V) and V²⁺
V: 1s²2s²sp⁶3s²3p⁶3d³4s² V²⁺: 1s²2s²sp⁶3s²3p⁶3d³
What is the charge on the titanium ion in TiO₂? a. +4 b. +2 c. +1 d. -1 e. -2
a. +4
Liquid oxygen boils at 90.19 K. What is this temperature in degrees Celsius? a. -182.96°C b. 90.19°C c. 182.96°C d. -90.19°C e. -273.15°C
a. -182.96°C
You have 5.00 g of calcium chloride, CaCl₂. Compute the following showing all of your work with correct units on all quantities and numbers expressed to the correct number of significant digits. a. How many moles of CaCl₂ b. How many moles of Chloride, Cl¹⁻ c. How many atoms of Ca²⁺
a. .0451 mol b. .0902 mol c. 2.72 x 10²² atoms
How many moles and how many grams of CaF2 would be needed to produce 1.18 moles of F2 given the two reactions below? Show and label all of your work including all units from conversions factors derived from the balanced equations below. CaF₂(s) + H₂SO₄(l) → 2HF(g) + CaSO₄(s) 2HF(l) → F₂(g) + H₂(g) a. How many moles of CaF₂ needed? b. How many grams of CaF₂?
a. 1.18 mol CaF₂ b. 92.1 g CaF₂
The atomic radius of a uranium atom is approximately 175 pm. In correct scientific notation, this is ________ a. 1.75 x 10⁻¹⁰ m b. 1.75 x 10⁻¹¹ m c. 1.75 x 10⁻¹² m d. 175 x 10⁻¹² m e. 1.75 x 10¹⁰ m
a. 1.75 x 10⁻¹⁰ m
White fuming nitric acid should contain no more than 2% water by mass. The water content in four samples was measured. What is the average value, and which measured value is closest to the average? Sample , % water (by mass) 1, 1.983 2, 1.927 3, 1.946 4, 1.956 a. 1.953, sample 4 b. 1.95, sample 4 c. 1.9530, sample 4 d. 1.9530, sample 3 e. 1.953, sample 3
a. 1.953, sample 4
Draw the valence bond picture of bonding in ethylene, which is shown below and answer the questions below (look up Lewis structure. a. Identify the number of valence electrons in the molecule b. The number of π bonds c. The number of σ bonds d. The hybridization of the carbon atomic orbitals
a. 12 b. 1 c. 5 d. sp²
Fill in the following for these isotopes: # of protons, # of neutrons, # of electrons. a. Chlorine-37 b. ¹³C c. ¹⁴C d. ²³Na¹⁺
a. 17, 20, 17 b. 6, 7, 6 c. 6, 8, 6 d. 11, 12, 10
A ³⁵Cl atom has ________ protons, ________ neutrons, and ________ electrons. a. 17; 18; 17 b. 17; 35; 17 c. 35; 17; 17 d. 18; 35; 17 e. 18; 17; 18
a. 17; 18; 17
In which orbital would an electron feel the highest effective nuclear charge? a. 3s b. 4s c. 3p d. 4p e. 3d
a. 3s
Draw the Lewis Structure and sketch the 3D molecular geometry for the molecule ClF₃ below. Include bond angles in your sketch. Answer the questions about your structure. a. What is the steric number for chlorine. b. Name the electron pair geometry. c. Name the molecular geometry. d. Is the molecule polar? Explain.
a. 5 b. trigonal bipyramidal c. t-shaped d. YES. Fluorine is more electronegative than carbon. The bond dipoles up and down cancel. That leave the one pointing to the left and that is the net dipole.
Which statement is true about the mole and molar mass? a. A mole is a number of particles equal to the number of atoms in exactly 12 g of carbon-12. b. A mole is a number of particles equal to the number of atoms in exactly 12 g of naturally occurring carbon. c. A mole is a number of particles equal to the number of atoms in exactly 16 g of oxygen-16. d. Molecular mass in amu and molar mass in grams per mole are independent of each other. e. The mole requires that the numbers of atoms in equal masses of different substances are equal.
a. A mole is a number of particles equal to the number of atoms in exactly 12 g of carbon-12.
a. Complete and balance the following reaction. b. Name the type of reaction this is. c. Write down the net ionic equation. (Hint: HCl is a strong acid) Al(OH)₃(s) + HCl (aq)→?
a. Al(OH)₃(s) + 3HCl(aq) → AlCl₃(aq) + 3H₂O(l) b. neutralization c. Al(OH)₃(s) + 3H⁺(aq) → Al³⁺(aq) + 3H₂O(l)
Using only the periodic table as a guide, arrange each set of particles by size, largest to smallest: a. Al, P, Cl, Ar b. Li⁺, Li, Na, K
a. Al>P>Cl>Ar b. K>Na>Li>Li⁺
Arrange the following elements in order of increasing first ionization energy: a. Mg, Ca, Sr, Ba b. P, S, Cl, Ar
a. Ba<Sr<Ca<Mg b. P<S<Cl<Ar
Which of the following elements would you expect to have the greatest first ionization energy? a. Br b. Ga c. Ge d. K e. Se
a. Br
Draw a three dimensional sketch of the following molecules: CF₂Cl₂, CH₂Cl₂, CH₂F₂, ClF₄, and CH₂Br₂. a. Which of these molecules has the largest dipole moment? Explain.
a. CH₂F₂ has the largest dipole moment. CH₂Cl₂ and CH₂Br₂ are less polar since Cl and Br both have smaller electronegativity than F. CF₂Cl₂ has the F dipole component of CH₂F₂ but it is partially canceled out by the Cl dipole moment pointing in the opposite direction. ClF₄ is nonpolar.
Which of the following has the largest atomic radius? a. Cs b. Rb c. Kr d. Xe e. I
a. Cs
Which of the following ionic compounds is insoluble in water? a. Cu₃(Po₄)₂ b. FeCl₃ c. NH₄CH₃COO d. AgNO₃ e. KSCN
a. Cu₃(Po₄)₂
Which straight-chain alkane below would you predict to be the most viscous? All are liquids exhibiting the general bonding pattern CH₃-(CH₂)η-CH₃ a. C₁₂H₂₆ b. C₁₀H₂₂ c. C₅H₁₂ d. C₆H₁₄ e. C₉H₂₀
a. C₁₂H₂₆
In which bond does the Cl atom have the highest electron density? a. H--Cl b. O--Cl c. S--Cl d. N--Cl e. Br--Cl
a. H--Cl (Explanation: Electronegativity difference is greatest in HCl)
Which of the following represents a physical property of water? a. It boils at 100°C. b. An electrical current decomposes water into hydrogen gas and oxygen gas. c. It reacts with iron metal and oxygen to form rust. d. It reacts with carbon monoxide to form carbon dioxide and hydrogen gas. e. It is used in photosynthesis.
a. It boils at 100°C.
You are given a liquid sample that contains methanol, ethanol, or a mixture of both. You use combustion analysis of a 0.336 g sample and obtain 0.462 g of CO₂ and 0.378 of H₂O. What did you learn about your sample? a. It is methanol. b. It is ethanol. c. It is more methanol than ethanol. d. It is more ethanol than methanol. e. It contains equal amounts of methanol and ethanol.
a. It is methanol.
Which gaseous compound below is likely to condense at the highest temperature (gas → liquid)? a. NH₃ b. NF₃ c. CF₄ d. PH₃ e. PF₃
a. NH₃
What is the correct formula for the compound formed between sodium and selenium based on their positions in the periodic table? a. Na₂Se b. NaSe₂ c. NaSe d. Na₂Se₂ e. Na₃Se
a. Na₂Se
Which of the following is an alkali metal? a. Rb b. Mg c. Al d. Cu e. Ca
a. Rb
Which of the following statements regarding orbitals and wave functions is true? a. Wave functions are mathematical solutions to the Schrödinger wave equation. b. Wave functions specify where an electron is at any given time. c. An orbital encloses a region in space around the nucleus where the probability of finding an electron is 1. d. The square of the wave function describes how the electron matter wave varies in time and space. e. All sine functions are solutions to the Schrödinger equation for the hydrogen atom.
a. Wave functions are mathematical solutions to the Schrödinger wave equation
Which of the following is the ground-state electron configuration of the Ca2+ ion? a. [Ar]4s²3d² b. [Ar]4s² c. [Ar]4s²4p2 d. [Ne]3s²3p⁶ e. [Ne]3s²3p⁸
a. [Ar]4s²3d²
Which type of bonding involves the sharing of valence electrons by two atoms? a. covalent b. ionic c. polar ionic d. intramolecular e. metallic
a. covalent
Extensive properties are ________ a. dependent on the amount of substance present. b. identical for all substances. c. independent of a substance's phase. d. the physical properties of a substance. e. dependent on the reactivity of the substance.
a. dependent on the amount of substance present.
Which subshell has only five orbitals? a. l=2 b. l=1 c. l=5 d. l=3 e. l=4
a. l=2
Which subatomic particles have approximately equal masses? a. protons and neutrons b. protons and electrons c. neutrons and electrons d.protons, neutrons, and electrons e. none of the above
a. protons and neutrons
Which of the following is NOT a pure substance? a. sparkling water b. gold metal c. oxygen gas d. water vapor e. dry ice (solid CO₂)
a. sparkling water
Which of the following is not an SI base unit? a. °C b. s c. kg d. mol e. m
a. °C
According to the law of definite proportions, ________ a. atoms forming a given compound react in variable proportions depending on conditions. b. different samples of the same compound contain the same proportions of the same elements. c. all compounds containing the same types of atoms have identical properties. d. all compounds containing the same types of atoms have relative masses that are whole- number multiples. e. only one type of molecule can be produced when two elements combine.
b. (different samples of the same compound contain the same proportions of the same elements.)
What is the formal charge of the nitrogen atom in hydrogen cyanide (HCN)? a. -1 b. 0 c. 1 d. 2 e. 5
b. 0
What l quantum numbers are possible when n=3? a. 1 and 2 b. 0,1,2 c. 1,2,4 d. 0,±1,±2 e. 0,±1,±2,±3
b. 0,1,2
Baking soda (NaHCO₃, 84.0 g/mol) can react with acids such as lactic acid (HC₃H₅O₃, 90.1 g/mol) to generate the carbon dioxide gas needed to make baked goods rise. If sufficient lactic acid is present to completely react with 20.4 g NaHCO₃, how many moles of CO₂ (44.01 g/mol) are generated? HC₃H₅O₃(aq) + NaHCO₃(s) → H₂O(l) + CO₂(g) + NaC₃H₅O₃(aq) a. 0.464 mol b. 0.243 mol c. 0.334 mol d. 0.204 mol e. 0.232 mol
b. 0.243 mol
In an experiment, 1.50 kg of concrete at 52.0°C is quickly transferred to 805 g of water at 19.0°C. The final temperature comes to 28.3°C. What is the approximate specific heat capacity of concrete? [cp(water) = 4.18 J/(g×°C)] a. 1.23 J/(g×°C) b. 0.880 J/(g×°C) c. 0.313 J/(g×°C) d. 0.533 J/(g×°C) e. 23.3 J/(g×°C)
b. 0.880 J/(g×°C)
At a certain elevation, the boiling point of water is 98.5C. How much energy is needed to heat 35.0 mL of water from 23.4C to the boiling point at this elevation? [cp = 4.18 J/(g × °C), d = 1.00 g/mL] a. 8.50 kJ b. 11.0 kJ c. 198 kJ d. 1.00 kJ e. 25.6 kJ
b. 11.0 kJ
If the following arithmetic operations are carried out, how many significant figures should be reported in the answer? 32 + 0.56 + 0.210 + 3.3 a. 1 b. 2 c. 3 d. 4 e. 5
b. 2
If the following arithmetic operations were carried out, how many significant figures should the answer contain? 0.750 × 11 / 9.250 a. 1 b. 2 c. 3 d. 4 e. 5
b. 2
If 120 g of NaOH (40.00 g/mol) were used to prepare 500.0 mL of solution, what would the concentration be? a. 1.0 M b. 2.0 M c. 3.0 M d. 4.0 M e. 6.0 M
b. 2.0 M
Which statement below regarding molecular orbitals for diatomic molecules is FALSE? a. An atomic orbital on one atom combines with an atomic orbital on the other atom to form two molecular orbitals. b. 2p atomic orbitals form only π and π* molecular orbitals. c. 2s atomic orbitals form only σ and σ* atomic orbitals. d. σ orbitals are symmetric with respect to rotation around the internuclear axis; π orbitals do not have this symmetry. e. A bonding molecular orbital describes the buildup of negatively charged electrons between the nuclei.
b. 2p atomic orbitals form only π and π* molecular orbitals.
Calculate the number of hydrogen atoms in 0.25 mol of strychnine, C₂₁H₂₂N₂O₂. a. 5.5 x 10²⁴ atoms b. 3.3 x 10²⁴ atoms c. 2.5 x 10²⁴ atoms d. 1.5 x 10²⁴ atoms e. 5.0 x 10²⁵ atoms
b. 3.3 x 10²⁴ atoms
Which of the following is NOT true regarding cations and anions? a. N³⁻ represents a nitrogen atom that has gained three electrons b. An oxygen molecule can lose an electron to form O₂⁻ c. Ca²⁺ represents a calcium atom that has lost two electrons d. The formation of a chlorine anion can be written as Cl + e⁻→ Cl⁻ e. N₂→N₂ +e⁻ describes a nitrogen molecule forming a +1 cation
b. An oxygen molecule can lose an electron to form O₂⁻
Which bond below is shortest? The number in parentheses is the bond energy. a. C -- C (348 kJ/mol) b. C -- F (453 kJ/mol) c. C -- H (411 kJ/mol) d. C -- Cl (339 kJ/mol) e. C -- O (358 kJ/mol)
b. C -- F (453 kJ/mol)
Which atom below can have an expanded octet? a. F b. Cl c. N d. B e. O
b. Cl
Caffeine has an elemental analysis of 49.48% C, 5.190% H, 16.47% O, and 28.85% N. It has a molar mass of 194.19 g/mol. What is the molecular formula of caffeine? a. C₄H₅N₂O b. C₈H₁₀N₄O₂ c. C₁₀H₁₄N₂O₂ d. C₆H₆NO₂ e. C₅H₇NO
b. C₈H₁₀N₄O₂
In a chemical reaction, bonds are broken, and new bonds are formed. Which statement below regarding bond energies is TRUE? a. Energy is released when bonds are broken. b. Energy is released when bonds are broken and more stable bonds are formed. c. Energy is released when bonds are broken and less stable bonds are formed. d. Bond energies and bond lengths generally are not correlated-that is, they vary independently. e. Bond energies and bond order are unrelated to each other.
b. Energy is released when bonds are broken and more stable bonds are formed.
In which bond does the H atom have the highest electron density? a. H--Cl b. H--Li c. H--N d. H--O e. H--C
b. H--Li
Which of the following is a chemical property of copper metal? a. It conducts heat. b. It reacts with nitric acid to produce copper(II) nitrate. c. It melts at 1085°C d. It conducts electricity. e. It has an orange color.
b. It reacts with nitric acid to produce copper(II) nitrate.
What is the symbol for potassium? a. P b. K c. Pt d. Po e. Pm
b. K
Radium is often found in uranium ores and can be separated from solutions by precipitation as radium sulfate. What is the formula for radium sulfate? a. RnSO₄ b. RaSO₄ c. Rn₂SO₃ d. Ra₂SO₄ e. Ra(SO₄)₂
b. RaSO₄
Which of the following statements is FALSE? a. As the wavelength of a photon decreases, its energy increases. b. The speed of a photon decreases as its wavelength decreases. c. Light can be viewed as packets of energy. d. As the frequency of a photon decreases, its energy decreases. e. A high-energy photon has a shorter wavelength than a low-energy photon.
b. The speed of a photon decreases as its wavelength decreases.
Which statement below regarding electron affinity is FALSE? a. Electron affinity values are usually negative because the association of an electron with a positive nucleus should produce an ion that is more stable. b. Zeff has no impact on electron affinity values. c. Electron affinities become more positive as atomic size increases. d. The electron affinities of the noble gases are positive or zero. e. Electron pairing in orbitals can have an impact on electron affinity.
b. Zeff has no impact on electron affinity values.
Which of the following objects, all moving at the same speed, will have the longest de Broglie wavelength? a. a proton b. an electron c. a baseball d. a neon atom e. a neutron
b. an electron
One reason electronegativity increases from left to right across a period is because of ________ a. increased shielding of valence electrons by the core electrons. b. an increase in the number of protons in the nucleus. c. a decrease in the effective nuclear charge (Zeff). d. an increase in the shielding of core electrons by the valence electrons. e. a decrease in the ionization potential.
b. an increase in the number of protons in the nucleus
A molecule ________ a. must contain at least two types of atoms. b. can be an element or a compound. c. cannot form a solid. d. cannot be broken into its constituent atoms by any means. e. can contain only one type of atom.
b. can be an element or a compound.
A pure substance ________ a. must be composed of atoms of the same type. b. cannot be separated into simpler substances by physical means. c. must be a compound. d. has different chemical properties depending on its source. e. can have a composition that varies from sample to sample.
b. cannot be separated into simpler substances by physical means.
Table sugar (sucrose, C₁₂H₂₂O₁₁) dissolves in water. This process ________ a. is a chemical change. b. is a physical change. c. produces a heterogeneous mixture. d. is a chemical property of sucrose. e. converts sucrose to carbon dioxide and water.
b. is a physical change.
When two liquids mix completely in all proportions, they are a. soluble b. miscible c. immiscible d. solvated e. ubiquitous
b. miscible
Which set of quantum numbers below is allowed? a. n= 2, l= 2, ml= 0, ms= -½ b. n= 7, l= 0, ml= 0, ms= +½ c. n= 7, l= -1, ml= -1, ms= -½ d. n= 1, l= 2, ml= 0, ms= +½ e. n= 5, l= 6, ml= -2, ms= -½
b. n= 7, l= 0, ml= 0, ms= +½
Which subatomic particles have opposite charges? a. protons and neutrons b. protons and electrons c. neutrons and electrons d. all protons e. all neutrons
b. protons and electrons
In quantum mechanics, an atomic orbital ________ a. provides the position of an electron at any instant of time in the space around an atomic nucleus. b. provides the probability of finding an electron at any point in the space around an atomic nucleus. c. is identical to the orbits Bohr used in his analysis of the hydrogen atom. d. identifies the most probable position of an atomic nucleus. e. locates all the electrons in an atom.
b. provides the probability of finding an electron at any point in the space around an atomic nucleus.
According to the first law of thermodynamics, which of the following will always increase the internal energy of a system? (q = energy transferred, w = work done) a. q > 0, w < 0 b. q > 0, w > 0 c. q < 0, w < 0 d. q < 0, w > 0 e. None will always increase the internal energy of a system.
b. q > 0, w > 0
If all of the lead (Pb) in a 1.65L solution is precipitated as 12.8 g lead(II) sulfate (303.26 g/mol), what is the molar concentration of Pb²⁺ in the solution? a. 0.0696 M b. 0.0422 M c. 0.0256 M d. 0.129 M e. 0.776 M
c. 0.0256 M
The diameter of the sun is approximately 1,390,000 km. In correct scientific notation, this is ________ a. 1.39 x 10⁻⁶ km b. 1.39 x 10⁻⁹ m c. 1.39 x 10⁶ km d. 139 x 10⁴ km e. 1.39 x 10³ m
c. 1.39 x 10⁶ km
What are the ideal bond angles around carbon in CH₂O? a.180° b. 90° c. 120° d. 109.5° e. 60°
c. 120° (Explanation: Carbon's steric number is 3 predicting trigonal planar geometry)
What is the energy (E, in joules) of a 6.00 × 10¹⁰ Hz photon from a microwave oven? a. 3.98 x 10⁻³⁰ J b. 3.98 x 10⁻³⁹ J c. 3.98 x 10⁻²³ J d. 3.98 x 10⁻¹⁷ J e. 3.98 x 10⁻¹³ J
c. 3.98 x 10⁻²³ J
A graduated cylinder is filled with water to the 25.0 mL mark. After 27.5 g of titanium dioxide (TiO₂) is added, the volume is 31.5 mL. Calculate the density of TiO₂. a. 0.873 g/cm³ b. 0.87 g/cm³ c. 4.2 g/cm³ d. 4.23 g/cm³ e. 2.05 g/cm³
c. 4.2 g/cm³
What is the formula unit mass of ammonium carbonate (NH₄)₂Co₃? a. 78.04 amu b. 82.02 amu c. 96.09 amu d. 102.07 amu e. 212.88 amu
c. 96.09 amu
Which of the following statements is NOT true? a. The relative numbers of each type of atom in a given compound do not vary. b. A compound always contains the same mass percentages of its constituent elements. c. A large sample and a small sample of a given compound contain the same number of each type of atom. d. A large sample and a small sample of a given compound contain the same types of atoms combined in the same proportions. e. A large sample and a small sample of a compound share the same chemical formula.
c. A large sample and a small sample of a given compound contain the same number of each type of atom
Which statement about electromagnetic radiation is NOT correct? a. Electromagnetic radiation consists of perpendicular oscillating electric and magnetic fields. b. Electromagnetic radiation is emitted by all stars. c. All electromagnetic radiation is visible to the eye. d. Electromagnetic radiation spans a very wide range of wavelengths, from gamma rays to radio waves. e. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other.
c. All electromagnetic radiation is visible to the eye.
Which of the following is NOT an element? a. Cs b. Au c. CS₂ d. Ar e. Co
c. CS₂
Which molecule below has a carbon atom that is sp³ hybridized? a. C₂H₂ b. C₂HF₃ c. C₂H₄Cl₂ d. C₂H₄ e. C₂H₂Cl₂
c. C₂H₄Cl₂
Which element below is expected to have the most negative electron affinity? a. C b. O c. F d. S e. Br
c. F
In its reaction with water, phenol (C₆H₅OH) acts as a weak acid. Which of the following statements is FALSE? a. Hydronium ions are produced. b. Ionization is not complete. c. It generates hydroxide ions. d. The pH of the solution at 25°C is less than 7. e. The ionization reaction reaches equilibrium.
c. It generates hydroxide ions.
Which compound below has the same molecular shape as CCl₃H? a. SF₄ b. KrF₄ c. SiF₄ d. C₂H₄ e. C₂H₂
c. SiF₄ (SN=4)
The layers in a particular gumball are (1) an outer layer of citric acid and malonic acid; (2) a layer of sugar and flavoring; (3) a layer of sodium bicarbonate (NaHCO₃); and (4) gum. When a person starts to eat one of these gumballs, s/he puckers, smiles, and then foams at the mouth before starting to chew the gum itself. Where did the foam come from? a. The sodium bicarbonate reacts with sugar, making carbon dioxide gas. b. The sodium bicarbonate explodes when exposed to moisture. c. The acids react with the sodium bicarbonate, making unstable carbonic acid. d. The flavoring contains a foaming agent. e. The acids react with the sugar, making a carbon volcano.
c. The acids react with the sodium bicarbonate, making unstable carbonic acid.
The reaction of nitrogen with oxygen to form nitrogen dioxide gas at 25°C and 1 atm requires approximately 66.4 kJ of thermal energy. The change in internal energy is about 68.9 kJ. Which statement below is true? 2N₂(g) + O₂→ 2NO₂(g) a. The reaction is exothermic and work is done on the system by the surroundings. b. The reaction is exothermic and work is done by the system on the surroundings. c. The reaction is endothermic and work is done on the system by the surroundings. d. The reaction is endothermic and work is done by the system on the surroundings. e. The heat and work associated with the reaction cannot be determined without more information.
c. The reaction is endothermic and work is done on the system by the surroundings.
Calcium is an example of ______ a. an alkali metal b. a transition metal c. an alkaline earth metal d. a halogen e. a chalcogen
c. an alkaline earth metal
Which one of the following is NOT an intensive physical property of a pure liquid? a. boiling point b. conductivity c. mass d. density e. color
c. mass
Protons and neutrons are examples of ________ a. nuclei b. nuclides c. nucleons d. isotopes e. charged particles
c. nucleons
A shell consists of all ________ a. electrons with the same quantum number b. orbitals with the same quantum numbers c. orbitals with the same principal quantum number d. electrons with the same magnetic quantum number e. orbitals with the same l and ml quantum numbers
c. orbitals with the same principal quantum number
What is the term used for odd-electron molecules? a. anions b. cations c. radicals d. isomers e. nonexistent
c. radicals
What is the molecular geometry of SF₄O? a. pentagonal b. tetrahedral c. trigonal bipyramidal d. trigonal planar e. square pyramidal
c. trigonal bipyramidal
In a steam engine, steam in a cylinder is compressed by a piston exerting 16.5 atm of external pressure. The volume of the cylinder decreases by 22.4 L, and simultaneously the steam heats up. If the total energy change of the steam is 42.6 kJ, calculate the heat flow into/out of the steam. (101.3 J × 1 L×atm) a. +80.0 kJ b. +37.4 kJ c. -37.4 kJ d. +5.2 kJ e. -5.2 kJ
d. +5.2 kJ
Which of the following is NOT an allowed value for the principal quantum number? a. 1 b. 3 c. 10 d. 0 e. 2
d. 0
The period at the end of this sentence has an area of approximately 0.2 mm². One carbon atom, having a diameter of about 160 pm, covers an area of about 0.02 nm². How many carbon atoms would be required to produce a one-atom-deep layer that covers 0.2 mm²? a. 1x10¹² b. 2x10¹¹ c. 1x10⁷ d. 1x10¹³ e. 2x10⁶
d. 1x10¹³
How many unpaired electrons does Co³⁺ have? a. 0 b. 1 c. 3 d. 4 e. 6
d. 4
TNT, or trinitrotoluene, has the chemical formula C₇H₅N₃O₆. How many grams of nitrogen are present in 25 g TNT (227.13 g/mol)? a. 0.11 g b. 0.33 g c. 1.5 g d. 4.6 g e. 5.4 g
d. 4.6 g
What is the frequency (in hertz) of the photons emitted by a HeNe laser with a wavelength (λ) of 632.8 nm? a. 4.738 x 10⁵ Hz b. 1.897 x 10² Hz c. 1.897 x 10¹¹ Hz d. 4.738 x 10¹⁴ Hz e. 1.897 x 10¹⁴ Hz
d. 4.738 x 10¹⁴ Hz
At what velocity would a proton be traveling if it had the same kinetic energy as an electron traveling at 10.0% of the speed of light? KE=½mu², where m is the mass and u is the velocity, proton mass= 1.673x10⁻²⁷kg; electron mass=9.109x10⁻³¹kg; speed of light = 2.998 x 10⁸ m/s a. 4.89 x 10¹¹ m/s b. 2.45 x 10¹¹ m/s c. 4.95 x 10⁵ m/s d. 7.00 x 10⁵ m/s e. 3.50 x 10⁵ m/s
d. 7.00 x 10⁵ m/s
Licopene, a red pigment found in tomatoes, has the empirical formula C₅H₇, and its molecular mass is found to be approximately 537 amu. How many empirical units are in the actual molecular formula? a. 1 b. 2 c. 4 d. 8 e. 10
d. 8
Which of the following statements is NOT true? a. The relative numbers of each type of atom in a given compound do not vary. b. A compound always contains the same mass percentages of its constituent elements. c. A large sample and a small sample of a given compound contain the same number of each type of atom. d. A large sample and a small sample of a given compound contain the same types of atoms combined in the same proportions. e. A large sample and a small sample of a compound share the same chemical formula. Which of the following statements is NOT true? a. Given that the chemical formula of methanol is CH4O, the number of carbon atoms in a sample of methanol will be the same as the number of oxygen atoms. b. If a compound is 75% carbon and 25% hydrogen by mass, 12 g of the compound contains 9 g C and 3 g H. c. If a compound contains 76 g of chlorine and 12 g of carbon, it will always have a 6.33:1 mass ratio of Cl to C. d. A compound containing 17.1 g of phosphorus and 58.9 g of chlorine has the same identity as a compound containing 35.7 g P and 204.3 g Cl. e. A compound containing 106.6 g of copper and 13.4 g of oxygen has the same identity as a compound containing 159.9 g Cu and 20.1 g O.
d. A compound containing 17.1 g of phosphorus and 58.9 g of chlorine has the same identity as a compound containing 35.7 g P and 204.3 g Cl.
Which molecule below is NOT polar? a. NO₂ b. H₂O c. SO₂ d. CS₂ e. N₂O
d. CS₂
Which compound below will have the strongest dipole-dipole interactions between its molecules? a. CF₄ b. CO₂ c. CH₃F d. H₂CO e. CH₃Cl
d. H₂CO
Which molecule or ion below is linear? a. H₂Se b. H₂S c. ICl₃ d. IBr₂⁻ e. SO₂
d. IBr₂⁻
Which group of elements is listed in order of increasing electronegativity? a. F<Cl<Ge<Sn b. Rb<Ca<Sc<Cs c. Zr<V<Nb<Ta d. In<Ga<Al<C e. Cl<Br<I<F
d. In<Ga<Al<C (Explanation: Electronegativity increases going up and to the right on the periodic table.)
Which row 2 element probably has the following successive ionization energies: IE₁, 1314 IE₂, 3389 IE₃, 5298 IE₄, 7471 IE₅, 10,992 IE₆, 13,329 IE₇, 71,345 IE₈, 84,087 a. Be b. B c. N d. O e. Ne
d. O
Which of the following elements has the ground-state electron configuration 1s²2s²2p⁶3s²3p³? a. Al b. S c. Cl d. P e. Ar
d. P
Which molecule or ion below has a central atom with the same hybridization as PCl₅? a. IF₆⁺ b. SiF₄ c. BrF₅ d. SbF₅ e. XeF₄
d. SbF₅
Which statement regarding a α bond between two carbon atoms linked by a single bond is FALSE? a. The region of electron density lies along the bond axis connecting the nuclei of the two atoms. b. The bond can be described by the overlap of sp hybrid orbitals from each atom. c. The bond can be described by the overlap of sp² hybrid orbitals from each atom. d. The bond can be described by the overlap of sp³d hybrid orbitals from each atom. e. The bond can be described by the overlap of an sp² hybrid orbital from one atom with an sp³ hybrid orbital from the other atom.
d. The bond can be described by the overlap of sp³d hybrid orbitals from each atom
Which statement describing the properties of the different phases of a sample of matter is true? a. The particles in both the gas and liquid phases are highly ordered and in close proximity to one another. b. The particles in the liquid phase are highly compressible because they can slip past one another. c. The particles in both the solid and liquid phases are free to assume any shape, and their nearest neighbors change over time. d. The solid phase is rigid, even though its constituent particles may vibrate a little depending on their temperature. e. Localized areas of order can form in the gas phase because the particles experience significant attractions to one another.
d. The solid phase is rigid, even though its constituent particles may vibrate a little depending on their temperature.
Which of the following statements about the angular momentum quantum number, l, is true? a. It reflects the size of an orbital. b. It determines the energy of an orbital. c. Its value must be a positive integer. d. There are 2l + 1 orbitals in a subshell. e. Each value specifies the location of at most two electrons.
d. There are 2l + 1 orbitals in a subshell.
You synthesize a cation with a +1 charge by oxidizing a compound made by combining one volume of iodine vapor with six volumes of fluorine gas. What F — I — F bond angle value(s) would you predict? a. all 120° b. three 120° and four 90° c. three 90° and four 120° d. all 90° e. none of these
d. all 90°
Which of the following lasers emits photons with the highest frequency? a. a Nd:YAG laser with λ = 1064 nm b. an Ar⁺ laser with λ = 514.5 nm c. a Kr⁺ laser with λ = 647 nm d. an ArF laser with λ = 193 nm e. a HeNe laser with λ = 633 nm
d. an ArF laser with λ = 193 nm
In Popper's epistemology, hypotheses a. come from a logical inductive process given experimental evidence b. are nonscientific c. must be justified from experimental evidence d. are guesses
d. are guesses
Elements in group 17 (VIIA) are called ________ a. alkali metals b. pnictogens c. alkaline earth metals d. halogens e. chalcogens
d. halogens
The correct H--N--H bond angle in NH₃ is ________ a. the same as the H — O — H angle in water b. exactly 109.5° c. greater than 109.5° d. less than 109.5° e. 120°
d. less than 109.5°
Which element forms an ionic compound with the formula Na₃X? a. magnesium b. carbon c. iodine d. phosphorus e. sulfur
d. phosphorus
Which of the following would be the best conductor of electricity when dissolved in water? a. iodine, I₂(aq) b. ethylene glycol, HOCH₂CH₂OH(aq) c. methanol, CH₃OH d. sodium hydroxide, NaOH(aq) e. carbon dioxide, CO₂(aq)
d. sodium hydroxide, NaOH(aq)
At the critical point, ________ a. all the liquid has evaporated. b. the densities of the solid and liquid are the same. c. the densities of the solid and the gas are the same. d. the densities of the gas and the liquid are the same. e. a critical mass has been reached.
d. the densities of the gas and the liquid are the same.
Isotopes have ________ a. the same atomic mass. b. the same total number of protons and neutrons. c. the same number of neutrons but a different number of protons. d. the same number of protons but a different number of neutrons. e. the same number of protons but different numbers of electrons.
d. the same number of protons but a different number of neutrons.
Elements 21 through 30 are known as ________ a. alkaline earths b. chalcogens c. halides d. transition metals e. rare earths
d. transition metals
On average, the total body content of cholesterol in a 150 lb person may be around 35 grams. If the mass of one cholesterol molecule (C₂₇H₄₆O) is about 6.4 x 10⁻²² g, how many cholesterol molecules are present in this person? a. 3.5 x 10⁻²³ molecules b. 1.8 x 10⁻²³ molecules c. 1.8 x 10²² molecules d. 6.4 x 10²² molecules e. 5.5 x 10²² molecules
e. 5.5 x 10²² molecules
The work function of sodium is Φ=2.90 x 10⁻¹⁹ J. What is the maximum wavelength that can cause the ejection of photoelectrons from a sodium surface? a. 151 nm b. 222 nm c. 45.1 nm d. 451 nm e. 685 nm
e. 685 nm
Gallium has two naturally occurring isotopes with the following masses and natural abundances. Calculate the average atomic mass of Ga. ⁶⁹Ga 68.9256 amu 60.108% ⁷¹Ga 70.9247 amu 39.892% a. 69.925 amu b. 70.127 amu c. 70.000 amu d. 69.824 amu e. 69.723 amu
e. 69.723 amu
What is the mass of one ozone molecule, O₃, in grams? Round your answer to two significant figures.(1 amu = 1.6605 x 10⁻²⁷ kg) a. 4.8 x 10¹g b. 2.9 x 10²⁵g c. 1.3 x 10²²g d. 5.3 x 10⁻²³g e. 8.0 x 10⁻²³ g
e. 8.0 x 10⁻²³ g
How many orbitals are possible for the n = 3 shell? a. 1 b. 2 c. 3 d. 6 e. 9
e. 9
Which statement below about bonds between two carbon atoms is/are TRUE? (I) Bond strength increases as more electrons are shared between the atoms. (II) Bond strength increases as the overlap between atomic orbitals increases. (III) Hybrid orbitals account for the observed geometry and bond angles around each carbon atom. a. I b. II c. III d. Only two of these are correct statements. e. All three are correct statements.
e. All three are correct statements.
Which two elements would you expect to show the most similar behavior? a. Se and Br b. B and C c. Li and Be d. Sn and Bi e. Ca and Sr
e. Ca and Sr
Which statement below regarding allotropes is FALSE? a. Allotropes of an element have different structures. b. Allotropes of an element have different chemical and physical properties. c. Not all elements have multiple allotropes. d. Oxygen and ozone are examples of allotropes. e. Carbon dioxide and carbon monoxide are examples of allotropes.
e. Carbon dioxide and carbon monoxide are examples of allotropes.
Which statement below regarding the physical state of a substance is true? a. All substances expand as they melt or boil. b. The physical state observed is largely independent of attractive forces between the substance's constituent particles. c. The physical state observed depends only on temperature. d. The solid and liquid phases are unaffected by changes in pressure. e. Changes in temperature cause changes in the energies of the substance's constituent particles.
e. Changes in temperature cause changes in the energies of the substance's constituent particles.
In terms of the enthalpy of formation, which of the following compounds is the most unstable compared to its elements under standard conditions? a. KCl(s),∆H°f = -435.9 kJ/mol b. PH3(g), ∆H°f = +5.4 kJ/mol c. Fe3O4(s), ∆H°f = -117.1 kJ/mol d. NiO(s), ∆H°f = -239.7 kJ/mol e. ICl(g), ∆H°f = +17.8 kJ/mol
e. ICl(g), ∆H°f = +17.8 kJ/mol
The mathematical description of an electron as a wave was developed by ________ a. Bohr b. Heisenberg c. Einstein d. de Broglie e. Schrödinger
e. Schrödinger
Which of the following is a homogeneous mixture? a. an egg b. smoke c. beach sand d. dry ice (solid CO₂) e. a salt solution (NaCl dissolved in water)
e. a salt solution (NaCl dissolved in water)
The solubility of a compound may depend on many factors, including a. solute-solvent interactions b. solute-solute interactions c. solvent-solvent interactions d. physical parameters such as temperature e. all of the items listed
e. all of the items listed
Ethanol has the formula CH₃CH₂OH. The oxygen atom has a ________ local molecular geometry and ________ hybridization. a. trigonal planar; sp b. tetrahedral; sp³ c. bent; sp² d. trigonal planar; sp² e. bent; sp³
e. bent; sp³
Coulomb's law states that the interaction energy between ions depends ________ a. only on the ionic charges. b. only on the distance between the ions. c. directly on both the ionic charges and the distance between the ions. d. on the temperature. e. directly on the ionic charges and inversely on the distance between the ions.
e. directly on the ionic charges and inversely on the distance between the ions.
A student conducts repeated trials to determine the density of a sample of seawater and obtains the following results: 1.321 g/mL, 1.323 g/mL, 1.319 g/mL, and 1.321 g/mL. Known values are reported to be in the 1.02 to 1.09 g/mL range. The experimental results are ________ a. less precise than the known values. b. more accurate than the known values. c. imprecise but accurate. d. precise and accurate. e. inaccurate but precise.
e. inaccurate but precise.
Which statement below regarding molecular orbital theory is TRUE? a. Two bonding orbitals and two antibonding orbitals are formed from one atomic orbital on each of two atoms. b. p atomic orbitals cannot form σ molecular orbitals. c. A 2s σ orbital has a higher energy than a 2s σ* orbital. d. Only π molecular orbitals can be formed from p atomic orbitals. e. s atomic orbitals can only form σ molecular orbitals.
e. s atomic orbitals can only form σ molecular orbitals.
Which transition in a hydrogen atom will cause emission of the shortest wavelength photon? a. ηinitial =5 to ηfinal = 3 b. ηinitial =4 to ηfinal = 3 c. ηinitial =4 to ηfinal = 2 d. ηinitial =3 to ηfinal = 2 e. ηinitial =3 to ηfinal = 1
e. ηinitial =3 to ηfinal = 1