Chem I final
Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?
Elements that are within the same period
What is the correct formula for the compound formed between potassium and phosphorus based on their positions in the periodic table? K2P KP2 KP K2P2 K3P
K3P
Identify the binary compound that has ionic bonding. H2O NO LiF CH4 CF4
LiF
Which one of the following is *not* classified correctly? Distilled water is a compound. Gold is an element. Air is a solution. Table salt (sodium chloride) is a mixture. Salad dressing is a suspension.
Table salt (sodium chloride) is a mixture.
Which statement about isotopes of the same element is *not* correct? They have the same number of protons. They have different numbers of neutrons. They have essentially the same chemical properties. They have the same atomic mass. They have the same number of electrons.
They have the same atomic mass.
If not handled carefully, ammonium perchlorate can decompose violently according to the thermochemical equation below. 2 NH4ClO4(s) → N2(g) + Cl2(g) + 2 O2(g) + 4 H2O(g) ΔH = −375.6 kJ The enthalpy of formation of H2O(g) is −241.8 kJ. Calculate the enthalpy of formation of ammonium perchlorate
−295.8 kJ
A mass of 11.60 g of phosphoric acid was produced from the reaction of 10.00 g of P4O10 with 12.00 g water. What was the percent yield for this reaction?
84.00%
In one analysis, 3.01 x 1013 molecules of ozone (O3) were found in 1.00 mL of an air sample. How many moles of ozone is this? A. 5.00 x 10-11 mol B. 5.00 x 1037 mol C. 1.81 x 1037 mol D. 6.02 x 10-23 mol E. 1.81 x 10-11 mol
A
Rutherford experiment provided insightful information regarding the constitution of the atom. The figure below shows three major observations from the experiment. Select the conclusion regarding the interpretation of the experimental observation "Some α particles are deflected by small angles": A. The atom's nucleus is positively charged. B. The atom's nucleus carries most of the mass. C. The atom is mostly empty space. D. The electrons carry a very small amount of the atom's mass. E. The atom does not have a nucleus.
A
When work is done on a system, w will be a ________ value. A. positive B. negative C. very large D. very small E. There is not enough information given to determine the answer.
A
Which one of the following statements is not correct? Sodium and chlorine are elements. Sodium chloride (table salt) is a compound. Sodium chloride is a pure substance. Sodium chloride is a heterogeneous mixture. Sodium chloride added to water forms a solution.
Sodium chloride is a heterogeneous mixture
What is the correct systematic name for Na2SO3?
Sodium sulfite
Which of the following is an ionic compound? SO2 ClO2 H2O V2O5 CO2
V2O5
________ is an example of an extensive property. Volume Density Boiling point Color Malleability
Volume
Place the following ions in order from smallest to largest ionic radii: Se2-, Sr2+, Y3+, and Br-
Y3+ < Sr2+ < Br- < Se2-
Spanish mahogany (a kind of wood) has a density of 53 lb/ft3. Would you be able to lift a piece of mahogany that measured 10 in x 12 in x 14 in?
Yes, it would weight about 50lb
Which of the following would you predict to be insoluble in water? NiSO4 Na3PO4 Ca(C2H3O2)2 FeCl3 ZnS
ZnS
l is known as the:
angular momentum quantum number, and it specifies the orbital shape
In order to exhibit delocalized π bonding, a molecule must have ________.
at least two resonance structures
According to VSEPR theory, if there are three electron domains in the valence shell of an atom, they will be arranged in a(n) ________ geometry.
bent
A pure substance
cannot be separated by physical means
A strong electrolyte is a solution/solute that
completely, or almost completely, ionizes or dissociates in a solution.
Valence bond theory does not address the issue of ________.
excited states of molecules
Deposition is the process in which a ________ is converted into a ________.
gas; solid
Elements in group 17 (VIIA) are called ________ alkali metals. pnictogens. alkaline earth metal. halogens. chalcogens.
halgoens
The first ionization energies of the elements ________ as you go from left to right across a period of the periodic table, and ________ as you go from the bottom to the top of a group in the table.
increase, increase
For a given arrangement of ions, the lattice energy decreases as ionic radius ________ and as ionic charge ________
increases, decreases
What is the correct name for FeCl3? iron(III) chloride iron trichloride ferrum trichloride ferric trichloride iron chloride
iron(III) chloride
A typical double bond ________.
is stronger and shorter than a single bond consists of one π bond and one π bond imparts rigidity to a molecule consists of two shared electron pairs
An example of a chemical property of formaldehyde (CH2O) is ________ it is flammable. it has a density of 1.09 g/mL. it is colorless. it dissolves in water. it is a gas at room temperature
it is flammable
Silicon is best described as a ________ metalloid. metal. transition metal. noble gas. nonmetal.
metalloid.
Oxygen is best described as a ________ metalloid. metal. transition metal. noble gas. nonmetal.
nonmetal
Bond enthalpy is always
positive
ΔH for an endothermic process is ________ while ΔH for an exothermic process is ________.
positive, negative
Which of the following mixtures can be separated by filtration? sugar dissolved in coffee sand and water gasoline alcohol dissolved in water air
sand and water
The law of constant composition states that ________
the elements forming a particular compound always combine in the same proportions.
One mole is defined as ________
the number of particles equal to the number of atoms in exactly 12 g of carbon-12
Using the VSEPR model, the electron-domain geometry of the central atom in O3 is ________.
trigonal planar
For a given process at constant pressure, w is positive. This means that the process involves ________.
work being done by the system on the surroundings
The symbol and name corresponding to the factor 10^-6 is
μ, micro
The most common sulfur ion has a charge of ________.
-2
Liquid nitrogen boils at 77 K. What is this temperature in °F?
-321°F
The value of ΔH° for the reaction below is -186 kJ. H2 (g) + Cl2 (g) → 2HCl (g) The value of ΔH°f for HCl (g) is ________ kJ/mol.
-93.0
Round the number 0.006734 to 2 significant figures
0.0067
Medicines usually are dispensed in units of mg. What is the mass of a 50 mg tablet?
0.050 grams
How many moles of mercury are there in 51.7 g of mercury?
0.258 mol
Cheetahs can run at speeds of up to 60 mi per hour. How many seconds does it take a cheetah to run 10 m at this speed? (1 mi = 1.609 km)
0.37 s
Cheetahs can run at speeds of up to 60 mi per hour. How many seconds does it take a cheetah to run 10 m at this speed? (1 mi = 1.609 km) 0.37 s 0.10 s 56 s 18 s 0.43 s
0.37 s
An antibonding π orbital contains a maximum of ________ electrons.
1
How many femtoseconds are in a second?
1 x 10^15
The central atom in the O3 molecule has ________ nonbonded electron pair(s) and ________ bonded electron pair(s) in its valence shell.
1, 3
Which of the following length measurements is the shortest? a 1.1 cm button a 1.1 x 103 mm piece of string. a 1.1 μm long insect. a 1.1 x 10−4 km diameter coin. a 0.11 m piece of tape.
1.1 μm long insect.
How much energy is needed to heat 57.6 grams of ice at -15.00 °C to ice at -5.00 °C? specific heat (ice) = 2.10 J/g · °C
1.21 kJ
Air bags in cars inflate when an electrical spark activates sodium azide (NaN3) so that it decomposes to sodium metal, Na, and nitrogen gas, N2. In the balanced reaction equation, how many moles of nitrogen gas are formed for each mole of sodium azide?
1.5
The following measurements of the mass of an aspirin tablet were made by different students in a lab. Which set is the most precise? 1.513 g, 1.503 g, 1.522 g 1.513 g, 1.511 g, 1.450 g 1.513 g, 1.459 g, 1.533 g 1.513 g, 1.517 g, 1.512 g 1.513 g, 1.510 g, 1.523 g
1.513 g, 1.517 g, 1.512 g
At maximum, an d-subshell can hold ________ electrons
10
Which solution has the same number of moles of NaOH as 50.0 mL of 0.100 M solution of NaOH? 20.0 mL of 0.200 M solution of NaOH 25.0 mL of 0.175 M solution of NaOH 30.0 mL of 0.145 M solution of NaOH 50.0 mL of 0.125 M solution of NaOH 100.0 mL of 0.0500 M solution of NaOH
100.0 mL of 0.0500 M solution of NaOH
What volume (mL) of a concentrated solution of magnesium chloride (9.00 M) must be diluted to 350. mL to make a 2.75 M solution of magnesium chloride?
107
The H-C-H bond angle in the CH4 ion is approximately ________.
109.5
Determine the number of atoms across the diameter of a human hair given that the diameter of an atom is 0.1 nm and the diameter of a human hair is 0.1 mm.
10^6
The prefix nano corresponds to a factor of ________
10−9
The ion NO- has ________ valence electrons
12
A certain element consists of two stable isotopes. The first has a mass of 14.0031 amu and a percent natural abundance of 99.63%. The second has a mass of 15.001 amu and a percent natural abundance of 0.37%. What is the atomic mass of the element?
14.01 amu
Which of the following samples contains the greatest number of atoms? 152.11 g Cs 90.00 g Br 73.21 g Zn 140.87 g Sb 7.25 g Li
140.87 g Sb
A 24.5 mL aliquot of 0.0938 M H2SO4 (aq) is to be titrated with 0.0295 M NaOH (aq). What volume (mL) of base will it take to reach the equivalence point?
156
There are ________ σ bonds and ________ π bonds in H3C-CH2-CH=CH-CH2-C≡CH.
16, 3
Potassium superoxide reacts violently with water to produce potassium hydroxide and oxygen according to the following balanced equation. What would the temperature be if 5.0 g of KO2 reacts to produce a pressure of 1.0 atm and 2.0 L of O2 gas? 4KO2(s) + 2H2O(l) → 4KOH(s) + 3O2(g)
190 ºC
A molecular orbital can accommodate a maximum of ________ electron(s).
2
A possible value of the magnetic quantum number m l for a 5d electron is
2
Considering that PV = nRT, which one of these samples contains the smallest number of particles? STP = 0°C and 1 atm. 2.0 L of H2 at STP 2.0 L of N2 at STP 2.0 L of H2 at 25°C and 760 torr 2.0 L of N2 at 0°C and 900 torr 2.0 L of He at STP
2.0 L of H2 at 25°C and 760 torr
Which of the following is the most massive? 2.5 kg of oxygen gas 0.25 kg of iron 2.5 g of sodium chloride (table salt) 250 g of helium gas 250 mg of aluminum
2.5 kg of oxygen gas
What volume (mL) of a 5.45 M lead nitrate solution must be diluted to 820.7 mL to make a 1.41 M solution of lead nitrate?
212
Spanish mahogany (a kind of wood) has a density of 53 lb/ft3. What is the weight of a piece of mahogany that measured 8 in x 53 in x 17 in?
220 lb
How many milligrams are in 0.025 kilograms? 1000 mg = 1 g, 1000 g = 1 kg
25000mg
Which of the following reactions will result in a reduced total pressure? CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) 2N2O(g) → 2N2(g) + O2(g) 2HI(g) → H2(g) + I2(g) 2H2(g) + O2(g) → 2H2O(l)
2H2(g) + O2(g) → 2H2O(l)
A triple bond consists of ________ pairs of electrons shared between two atoms.
3
Based on molecular orbital theory, the bond order of the N N bond in the N2 molecule is ________.
3
How many equivalent resonance forms can be drawn for CO32-? (Carbon is the central atom.)
3
How many p-orbitals are occupied in a O atom?
3
If the following operations are carried out, how many significant figures should be reported in the answer? 213 - 0.32 + 2.3 - 57.432
3
How many hydrogen atoms must bond to silicon to give it an octet of valence electrons?
4
Which of the following are decomposition reactions? (1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l) (2) CaO (s) + CO2 (g) → CaCO3 (s) (3) Mg (s) + O2 (g) → MgO (s) (4) PbCO3 (s) → PbO (s) + CO2 (g)
4
Aroldis Chapman is a MLB relief pitcher who recorded the fastest pitch in a major league game, which was clocked at 105 mi per hour. What was this speed in m/s? (1 mi = 1.609 km)
46.9 m/s
How many protons, neutrons, and electrons are there in a neutral atom of the isotope of silver, named silver-109?
47 protons, 62 neutrons, 47 e-
What is the frequency (s−1) of electromagnetic radiation that has a wavelength of 5.2 m?
5.7 x 10^7 s-1
Glucose (C6H12O6) is oxidized by molecular oxygen to carbon dioxide and water. How many O2 molecules are needed for each molecule of glucose that is oxidized?
6
What is the coefficient for sodium hydroxide when the following equation is balanced? ___Na2SO4 + ___Al(OH)3 à ___Al2(SO4)3 + ___NaOH
6
There are ________ paired and ________ unpaired electrons in the Lewis symbol for a fluorine atom.
6, 1
Room temperature is often taken to be 25°C. What is this temperature in °F?
77°F
Ozone (O3) reacts with iodide (I-) and water to form iodine (I2), hydroxide (OH-), and oxygen (O2). Balance the following reaction equation and report the sum of the stoichiometric coefficients. O3 + I- + H2O --> I2 + OH- + O2
8
A reaction that takes place between dissolved barium nitrate and dissolved sodium sulfate results in formation of solid barium sulfate. Which equation describes this reaction? A. Ba(NO3)2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaNO3(aq) B. BaNO3(aq) + NaSO4(aq) → BaSO4(s) + NaNO3(aq) C. 2Ba(NO3)(aq) + Na2SO4(aq) → Ba2SO4(s) + 2NaNO3(aq) D. Ba(NO3)2(aq) + 2NaSO4(aq) → Ba(SO4)2(s) + 2NaNO3(aq) E. Ba(NO3)2(aq) + Na2SO4(aq) → BaSO4(aq) + 2NaNO3(s)
A
How many protons, neutrons and electrons are there in a neutral atom of the isotope of silver named silver-109? A. 47p, 62n, 47e− B. 47p, 109n, 47e− C. 109p, 47n, 109e− D. 62p, 47n, 62e− E. 62p, 109n, 62e−
A
What volume of 0.378 M hydroiodic acid (HI) is required to neutralize 21.6 mL of 0.520 M barium hydroxide, Ba(OH)2? A. 59.4 mL B. 5.83 mL C. 15.7 mL D. 29.7 mL E. 80.0 mL
A
Which one of the following is not one of the postulates of Dalton's atomic theory? A. Atoms are composed of protons, neutrons, and electrons B. All atoms of a given element are identical; the atoms of different elements are different and have different properties. C. Atoms of an element are not changed into different types of atoms by chemical reactions: atoms are neither created nor destroyed in chemical reactions. D. Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms. E. Each element is composed of extremely small particles called atoms.
A
Which of the following statements correctly describes the properties of a liquid? A liquid does not have a definite shape. A liquid occupies the entire volume of its container. A liquid is highly compressible. A liquid contains molecules which are separated from one another by large distances. A liquid is highly ordered, such that molecules remain rigidly in place
A liquid does not have a definite shape
Which of the following is not a pure substance? Air Nitrogen gas Oxygen gas Argon gas Table salt (sodium chloride)
Air
Consider the BEST Lewis structures of the following oxyanions: (i) NO2- (ii) NO3- (iii) SO32- (iv) SO42- (v) BrO3- In which of the ions do all X-O bonds (X indicates the central atom) have the same length?
All
Which of the following is *not* one of the postulates of Dalton's atomic theory? Atoms are composed of protons, neutrons, and electrons All atoms of a given element are identical' the atoms of different elements are different Each element is composed of extremely small particles called atoms Compounds are formed when atoms of more than one element combine
Atoms are composed of protons, neutrons, and electrons
If there are 0.505 g of NaCl left in a beaker that originally contained 75.0 mL of saltwater, what must have been the concentration of the original solution? A. 0.00647 M B. 0.115 M C. 0.0115 M D. 0.673 M E. 0.0673 M
B
The average adult exhales about 1.0 kg of carbon dioxide each day. How much oxygen is needed in metabolizing glucose (C6H12O6, 180 g/mol) to make that much carbon dioxide? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O A. 180 g B. 730 g C. 1800 g D. 1500 g E. 360 g
B
The most electronegative atom of the ones listed below is ________. B Al Ga In Tl
B
What is the correct systematic name for Na2SO3? A. sodium sulfate B. sodium sulfite C. sodium(II) sulfate D. disodium trisulfide E. disodium monosulfate
B
Which arrangement is correct for increasing atomic radius? A. C < N < F B. Se < Cu < Ca C. Rb < K < Li D. Xe < Ne < He E. Sc < Ge < Br
B
Which of the following is a possible set of quantum numbers for a 3d orbital? A. n = 3, l = 1, me= -1 B. n = 3, l = 2, me = 0 C. n = 3, l = 0, me = 0 D. n = 3, l = 1, me = 2 E. n = 3, l = 2, me = 3
B
The following salts are used in fireworks. Which one has an incorrect formula or is not named correctly? Li2CO3, lithium carbonate CaSO4, calcium sulfate BaNO3, barium nitrate CuO, copper(II) oxide NH4Cl, ammonium chloride
BaNO3, barium nitrate
Which of the following can have a variable composition?
Both a homogenous and heterogenous mixture
Which ion below has the largest radius? Cl- K+ Br- F- Na+
Br-
A food sample was burned in a bomb calorimeter containing water. How much thermal energy was produced when the temperature of the water and the calorimeter rose from 20.0°C to 25.0°C? The calorimeter had a heat capacity of 2917 J/°C with the water. A. 5.83 kJ B. 45.8 kJ C. 14.6 kJ D. 3.49 kJ E. 61.0 kJ
C
At what speed (m/s) must a 10.0-mg object be moving to have a de Broglie wavelength of 3.3 x 10-41 m? A. 4.1 m/s B. 1.9 x 10-11 m/s C. 2.0 x 1012 m/s D. 3.3 x 10-42 m/s E. 1.9 x 1013 m/s
C
Based on the activity series, which one of the reactions below will occur? A. Zn (s) + MnI2 (aq) → ZnI2 (aq) + Mn (s) B. SnCl2 (aq) + Cu (s) → Sn (s) + CuCl2 (aq) C. 2AgNO3 (aq) + Pb (s) → 2Ag (s) + Pb(NO3)2 (aq) D. 3Hg (l) + 2Cr(NO3)3 (aq) → 3Hg(NO3)2 + 2Cr (s) E. 3FeBr2 (aq) + 2Au (s) → 3Fe (s) + 2AuBr3 (aq)
C
Down a column in the periodic table, the ionization energy ________ A. increases because the n quantum number changes. B. increases because the l quantum number changes. C. decreases because the outer electrons are further from the nucleus. D. increases because the atomic number (nuclear charge) increases. E. changes little because the outer electrons all are in the same outer shell.
C
Gaseous argon has a density of 1.40 g/L at standard conditions. How many argon atoms are in 1.00 L of argon gas at standard conditions? A. 4.76 × 1022 B. 3.43 × 1025 C. 2.11 × 1022 D. 1.59 × 1025 E. 6.02 × 1023
C
Which of the following processes will require chemical methods? A. Distilling a saltwater mixture. B. Separating a homogeneous mixture into pure substances. C. Breaking a compound into its constituent elements. D. Separating a heterogeneous mixture into pure substances. E. All processes require chemical method for the separation.
C
Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties? A. H and He B. C and O C. O and S D. Si and P E. K and Ca
C
Which one of the following is a cation? NO3- SO2 Ca2+ Na O2
Ca2+
This element reacts with hydrogen to produce a gas with the formula HX. When dissolved in water, HX forms an acidic solution. X is ________.
Chlorine
Which of the following is an element? Cl2 H2O NaCl MgO HCl
Cl2
The law of constant composition applies to
Compounds
A gas forming a liquid is called ________.
Condensation
Oxidation and ________ mean essentially the same thing.
Corrosion
A 5.00-g sample of copper metal at 25.0 °C is heated by the addition of 133 J of energy. The final temperature of the copper is ________°C. The specific heat capacity of copper is 0.38 J/g-K. A. 35.1 B. 25.0 C. 45.0 D. 95.0 E. 70.0
D
An unknown solid was analyzed in order to ascertain its identity. The mass of the solid was found to be 385.8 g. When the solid was dropped into a graduated cylinder containing 45.5 mL of water, the water level rose to 65.2 mL. The most likely identity of the metal is: A. Aluminum, d = 2.72 g/mL B. Silver, d = 10.50 g/mL C. Lead, d = 11.34 g/mL D. Tungsten, d = 19.38 g/mL E. Platinum, d = 21.46 g/mL
D
Calculate the energy (J) change associated with an electron transition from n = 2 to n = 5 in a Bohr hydrogen atom. A. 6.5 x 10-19 J B. 5.5 x 10-19 J C. 8.7 x 10-20 J D. 4.6 x 10-19 J E. 5.8 x 10-53 J
D
Consider the following equation: Cu(NO3)2(aq) + Na2S(aq) → CuS(s) + 2NaNO3(aq) Select the net ionic equation for the reaction above: A. Cu2+(aq) + Na2S(aq) → CuS(s) + 2Na+ (aq) B. Cu2+(aq) + 2 NO3 -1 (aq) + Na2S(aq) → CuS(s) + 2Na+ (aq) + 2NO3 -1 (aq) C. Cu2+(aq) + 2Na+ (aq) + S 2− (aq) → CuS(s) + 2Na+ (aq) D. Cu2+(aq) + S 2− (aq) → CuS(s) E. Cu2+(aq) + 2NO3 -1 (aq) + 2Na+ (aq) +S 2− (aq) → CuS(s) + 2Na+ (aq) + 2NO3 -1 (aq)
D
The melting point of a solid is 28°F. This corresponds to A. 289 K. B. 306 K. C. 266 K. D. 271 K. E. 301 K.
D
What is the correct formula for lead(IV) oxide? A. Pb2O4 B. Pb4O2 C. PbO D. PbO2 E. Pb2O
D
When HCl(g) reacts with NH3(g) to form NH4Cl(s) according to the following equation, energy is released into the surroundings. HCl(g) + NH3(g) NH4Cl(s) Is this reaction endothermic or exothermic, and what is the sign of ΔH for this reaction? A. endothermic, + B. endothermic, - C. exothermic, + D. exothermic, - E. energy change is balanced by the surroundings, neutral
D
Which one of the following is an ionic compound? A. SO2 B. ClO2 C. H2O D. V2O5 E. CO2
D
Which compound has the atom with the highest oxidation number? A. CaS B. Al(NO2)3 C. NH4Cl D. Na3N E. MgSO3
E
Which one of the following is not a physical property? flammability electrical conductivity color density boiling point
Flammability
Mercury has a density of 13.6 g/cm3. Mercury exists as a liquid at room temperature. If you drop a piece of lead (the density of lead = 8.0 g/cm3) in a beaker containing mercury will the lead will ___________.
Float
Sulfur combines with oxygen and hydrogen to form two acids. Sulfuric acid has the formula ________, and sulfurous acid has the formula ________. H2SO4, H2SO3 H2SO3, H2SO4 HSO4, HSO3 HSO3, HSO4 H2SO3, H2SO2
H2SO4, H2SO3
Which of the following are paired incorrectly? HC2H3O2 - weak acid HClO4 - weak acid Ca(OH)2 - strong base NH3 - weak base HBr - strong acid
HClO4 - weak acid
Which of the following is NOT an example of matter? (a). Coal (b).Elemental oxygen (c). Trees (d).Heat
Heat
Which one of the following can be easily separated into its components with simple techniques like filtration or decantation?
Heterogenous mixtures
Precision of a measurement refers to
How close a measured number is to other measured numbers.
Accuracy of a measurement refers to
How close the measured number is to the known value.
Which element is solid at room temperature? Cl2 F2 Br2 I2 H2
I2
John Dalton postulated that all matter is composed of small particles called atoms. For this proposition to be considered a valid scientific theory, ________
It must be supported by experimental evidence and testingq
The SI unit of mass is
Kilogram
Which one of the following statements is not correct? Dry ice subliming is a physical change. Methanol burning is a chemical reaction. Sugar dissolving in water is a physical change. Bleaching your hair is a chemical change (reaction), even though it changes your physical appearance. Liquid water turning into steam is a chemical reaction.
Liquid water turning into steam is a chemical reaction.
Which of the following is an alkaline earth metal? K Mg Al Cu Na
Mg
Of the bonds below, ________ is the least polar. C-O N-O C-F S-O K-Br
N-O
Filtration can be used to separate components in a mixture based on differences in ________
Particle size
What is the correct formula for lead(IV) oxide?
Pb2O
Which group 6A element is a metal?
Polonium
Expressing a number in scientific notation
Removes any doubts about any ambiguous zeroes.
Determine the oxidation number of the underlined element in SO32−.
+4
How many tin atoms are there in a 88.5 g sample of tin? Selected Answer: 4.49 × 1023 atoms 8.08 × 1023 atoms 1.19 × 1024 atoms 2.42 × 1024 atoms 1.07 × 1024 atoms
4.49 × 1023 atoms
What is the value of q when 4.25 g of water heats up from 274 K to 300 K? The heat capacity of water is 4.18 J/gK.
4.62 x 102 J
Which polyatomic ion is not labeled correctly? NH4+ ammonium ClO4- perchlorate CN- cyanate NO3- nitrate
CN- cyanate
Based on the element s position in the periodic table, which statement below is not correct? The charge on an ion of sodium is 1+. The charge on an ion of magnesium is 2+. The charge on an ion of oxygen is 2 . The charge on an ion of chlorine is 1 . Ca 2+ has more electrons than Ar.
Ca 2+ has more electrons than Ar
Which one of the following is a metal? Li S I He Si
Li
Which statement regarding the organization of the periodic table is not correct? Mendeleev arranged known elements with similar chemical properties in columns. Mendeleev s predictions of the chemical properties of unknown elements facilitated their discovery. Mendeleev arranged the elements in order of increasing atomic mass. The modern periodic table arranges elements in order of increasing atomic number. The elements go from gases to liquids to solids in order down the columns in Mendeleev s periodic table.
The elements go from gases to liquids to solids in order down the columns in Mendeleev s periodic table
Metals can be ________ at room temperature.
solid or liquid
A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water: Mg3N2 + 3H2O → 2NH3 + 3MgO The yield of MgO is 3.60 g. What is the percent yield in the reaction? A) 94.5% B) 78.4% C) 46.6% D) 49.4% E) 99.9%
B
A certain element consists of two stable isotopes. The first has a mass of 14.0031 amu and a percent natural abundance of 99.63%. The second has a mass of 15.001 amu and a percent natural abundance of 0.37%. What is the atomic mass of the element? A. 13.95 amu B. 13.98 amu C. 14.01 amu D. 14.50 amu E. 19.50 amu
C
Spanish mahogany has a density of 53. lb/ft3 . What is the weight of a piece of mahogany that measured 8.0 in x 53. in x 17. in? (12. in = 1 ft) A. 3.1 x 104 lb. B. 250. lb. C. 220 lb. D. 50. lb. E. 3.8 x 105lb.
C
The molecular formula of aspartame, the generic name of NutraSweet®, is C14H18N2O5. The molar mass of aspartame, rounded to the nearest integer, is ________ g. A. 24 B. 156 C. 294 D. 43 E. 39
C
Consider the general valence electron configuration of ns2 np 5 and the following statements: (i) Elements with this electron configuration are expected to form -1 anions. (ii) Elements with this electron configuration are expected to have large positive electron affinities. (iii) Elements with this electron configuration are nonmetals. Which statements are true? A. (i) and (ii) B. (i), (ii), and (iii) C. (ii) and (iii) D. (i), and (iii) E. All statements are false.
D
For which one of the following reactions is the value of ΔH°rxn equal to ΔH°f for the product? A. 2Ca (s) + O2 (g) → 2CaO (s) B. C2H2 (g) + H2 (g) → C2H4 (g) C. 2C (graphite) + O2 (g) → 2CO (g) D. 3Mg (s) + N2 (g) → Mg3N2 (s) E. C (diamond) + O2 (g) → CO2 (g)
D
How many milligrams are in 0.025 kilograms? 1000 mg = 1 g, 1000 g = 1 kg. A. 25 mg B. 250 mg C. 2500 mg D. 25000 mg E. 250000 mg
D
Identify the acid in the following acid-base reaction. PbCO3(s) + H2SO4(aq) PbSO4(s) + CO2(g) + H2O(l) A. PbCO3(s) B. H2O(l ) C. CO2(g) D. H2SO4(aq) E. PbSO4(s)
D
A 1.000 g sample of a hydrocarbon (which is a compound that contains only carbon and hydrogen) was burned in oxygen, and the carbon dioxide and water produced were carefully collected and weighed. The mass of the carbon dioxide was 3.385 g, and the mass of the water was 0.692 g. What was the empirical formula of the hydrocarbon? A. C5H12 B. C5H6 C. C1H6 D. C1H2 E. C1H1
E
A pure substance ________ A. can have a composition that varies from sample to sample. B. must be an element. C. has different chemical and physical properties depending on its source. D. must be a compound. E. can not be separated into simpler substances by physical means.
E
A tin atom has 50 electrons. Electrons in the ________ subshell experience the lowest effective nuclear charge. A. 1s B. 3p C. 3d D. 5s E. 5p
E
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. locates all the electrons in an atom. 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. provides the probability of finding an electron at any point in the space around an atomic nucleus.
E
Select is the best answer to report for the operation: (515 x 0.0025) + 24.57 A. 25.858 B. 25.86 C. 25.8575 D. 26 E. 25.9
E
The energy of a photon that has a wavelength of 12.3 nm is ________ J. (1x10-9 m = 1 nm.) A. 1.61 x 101 B. 6.18 x 1016 C. 1.99 x 10-25 D. 2.72 x 10-50 E. 1.62 x 10-17
E
Use the following information to determine the enthalpy for the reaction shown below. S(s) + O2(g) SO2(g) ΔH o = ? S(s) + O2(g) SO3(g) ΔH o = -395 kJ 2SO2(g) + O2(g) 2SO3(g) ΔH o = -198 kJ A. -593 kJ B. +296 kJ C. +593 kJ D. -989 kJ E. -296 kJ
E
When the following equation is balanced, the coefficients are ________. C8H18 + O2 → CO2 + H2O A. 2, 3, 4, 4 B. 1, 4, 8, 9 C. 2, 12, 8, 9 D. 4, 4, 32, 36 E. 2, 25, 16, 18
E
With which of the following will the Potassium ion form an insoluble salt? A. Phosphate B. Sulfate C. Sulfide D. Iodide E. Potassium will form soluble salts with all choices.
E
Phthalocyanine is a large molecule used in printing inks and dyes for clothing due to its insolubility in most solvents, its chemical stability, and its intense blue color. Elemental analysis showed that it consists of 74.69% C, 3.525% H, and 21.77% N, and has a molar mass of 514.54 g/mol. What is the molecular formula for phthalocyanine?
C32H18N8
During winter in Siberia, a tenant in a high-rise apartment building dumped a liter of steam (gaseous water) from a container off his balcony. Before it reached the ground, solid snow formed without observation of liquid water. The phase transition described by this process is called ________.
Deposition
Identify the incorrect statement(s). A solution ________ I. can be a solid, liquid, or gas. II. can be heterogeneous or homogeneous. III. is a homogeneous mixture.
Only II is incorrect
When you place a piece of dry ice (solid carbon dioxide) on a plate at room temperature, you notice that no liquid forms, unlike ice that melts to form liquid water. This is because dry ice ________
Sublimes instead of melting