Chem Final Exam Old Test Questions
Identify the correct net ionic equation for the reaction that occurs when solutions of Na3PO4 and Ca(NO3)2 are mixed.
3Ca^2+(aq) + 2PO4^3-(aq) → Ca3(PO4)2(s)
Concerning the electron configuration of aluminum, 1s22s22p63s23p1, which of the following represents the valence electrons only?
3s2 3p1
Assuming the octet rule is obeyed, how many covalent bonds will a carbon atom form to give a formal charge of zero?
4
A ground-state atom of iron has ___ unpaired electrons and is _____.
4, paramagnetic
Which of the elements listed below would most likely form an ionic bond when bonded to oxygen? A) Cl B) Ca C) H D) O E) C
B) Ca
Which of the following elements is found as a monatomic species in its most stable form? A) fluorine B) sulfur C) nitrogen D) neon E) chlorine
D) neon
Charles Law states that the volume of a fixed amount of gas maintained at constant pressure is inversely proportional to the absolute temperature of the gas. T or F
False
The heat of solution of NH4NO3 is 26.2 kJ/mol. Heat is evolved when a solution of NH4NO3 is diluted by addition of more water. T or F
False
Which element has the following ground-state electron configuration? [Ar]4s23d104p5
bromine
The name for CuSO4·5H2O is
copper(II) sulfate pentahydrate.
Which ground-state atom has an electron configuration described by the following orbital diagram? INCOMPLETE
selenium
Which of the following processes always results in an increase in the energy of a system?
The system gains heat and has work done on it by the surroundings.
Chemical energy is
the energy stored within the structural units of chemical substances.
The electron affinity of fluorine is essentially equal to
the ionization energy F-.
If a hydrogen atom and a helium atom are traveling at the same speed...
the wavelength of the hydrogen atom will be about 4 times longer than the wavelength of the helium atom.
Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g·°C) at 100°C is placed in contact with a 50.0 g block of iron (specific heat = 0.4494 J/g·°C) at 0°C, and the two blocks are insulated from the rest of the universe. The final temperature of the two blocks
will be lower than 50°C.
The total number of valence electrons in the ion SO42- is
32.
A solution may contain only one solvent but many solutes. T or F
False
During volcanic eruptions, hydrogen sulfide gas is given off and oxidized by air according to the following chemical equation: 2H2S(g) + 3O2(g) → 2SO2(g) + 2H2O(g) Calculate the standard enthalpy change for the above reaction given:
-1036.1 kJ/mol
Glycine, C2H5O2N, is important for biological energy. The combustion reaction of glycine is given by the equation 4C2H5O2N(s) + 9O2(g) → 8CO2(g) + 10H2O(l) + 2N2(g) ΔH°rxn = -3857 kJ/mol Given that ΔH°f[CO2(g)] = -393.5 kJ/mol and ΔH°f[H2O(l)] = -285.8 kJ/mol, calculate the enthalpy of formation of glycine.
-537.2 kJ/mol
How many electrons are in the 4p subshell of vanadium?
0
What is the formal charge on sulfur in the most favorable Lewis structure for the SCN- (thiocyanate) ion based on minimizing formal charge overall?
0
A 45 mL sample of nitrogen gas is cooled from 135oC to 15°C in a container that can contract or expand at constant pressure. What is the new volume of the nitrogen gas?
32mL
How many moles of Cl atoms are there in 65.2 g CHCl3?
1.64 mol
What is the binding energy (in J/mol or kJ/mol) of an electron in a metal whose threshold frequency for photoelectrons is 2.50 × 1014 /s?
1.66 × 10-19 J/mol
The SI prefixes kilo and milli represent, respectively:
10^3 and 10^-3
The reaction that represents the standard enthalpy of formation for sucrose (C12H22O11) is: INCOMPLETE
12 C(graphite) + 11 H2(g) + 11/2 O2(g) → C12H22O11 (s)
What is the minimum mass of sulfur dioxide necessary to produce 200. g of sulfuric acid in the following reaction? 2SO2 + O2 + 2H2O → 2H2SO4
131g
Consider a neutral atom of the following isotope of sulfur:34/16 S How many electrons, protons, and neutrons does the atom contain?
16 electrons, 16 protons, and 18 neutrons
Calculate the wavelength of a neutron that has a velocity of 250 cm/s. (The mass of a neutron = 1.675 × 10-24 g)
160 nm
An average home in Colorado requires 20. GJ of heat per month. How many grams of natural gas (methane) must be burned to supply this energy? (1 GJ = 109 J) CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) ΔH°rxn= -890.4 kJ/mol
3.6×10^5g
A beaker contains 115 g of ethanol at 18.2°C. If the ethanol absorbs 1125 J of heat without losing heat to the surroundings, what will be the final temperature of the ethanol? The specific heat of ethanol is 2.46 J/g×°C.
22.2°C
Aluminum metal reacts with nitric acid to produce aluminum nitrate and hydrogen gas. Identify the balanced reaction that describes this process.
2Al + 6HNO3 → 2Al(NO3)3 + 3H2
After carrying out the following operations, how many significant figures are appropriate to how in the result? (13.7 + 0.027) ÷ 8.221
3
What is the coefficient of H2O when the equation below is properly balanced? ___ PCl3(l) + ___ H2O(l) → ___ H3PO3(aq) + ___ HCl(aq)
3
During a titration the following data were collected. A 10. mL portion of an unknown monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were required to neutralize the sample. What is the molarity of the acid solution?
4.0 M
Calculate the frequency of visible light having a wavelength of 686 nm.
4.37 × 1014 /s
Convert 4.89 mm to μm.
4.89 x 103 μm
MAss number, Protons, Neutrons, Electrons of 40Ca^+2
40, 20, 20, 18
Which of the following represents the largest mass? A)2.0×102 cg B) 0.0010 kg C) 10.0 dg D)2.0×102 mg E)1.0×105 ng
A)2.0×102 cg
Which one of the following molecules has an atom with an expanded octet? A) HCl B) AsCl5 C) Cl2 D) ICl E) NCl3
B) AsCl5
Express the number 0.000053 in scientific notation.
5.3 × 10-5
Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25°C and 1.0 atm. R = 0.08206 L×atm/K×mol.
53.7 L
What is the maximum number of electrons in an atom that can have the following quantum numbers? n = 3, l = 1
6
What is the area, in square centimeters, of an 8.5 inch by 11 inch sheet of paper? (1 inch = 2.54 cm)
6.0 × 102 cm2
For phosphorus atoms, which ionization energy will show an exceptionally large increase over the previous ionization energy?
6th
How many valence electrons does P3- have?
8
A 20.00 mL sample of 0.1015 M nitric acid is introduced into a flask, and water is added until the volume of the solution reaches 250. mL. What is the concentration of nitric acid in the final solution?
8.12 × 10-3 M
A gas is allowed to expand, at constant temperature, from a volume of 1.0 L to 10.1 L against an external pressure of 0.50 atm. If the gas absorbs 250 J of heat from the surroundings, what are the values of q, w, and ΔE? INCOMPLETE
A
Which of the following processes is exothermic? A) CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) B) CO2(g) + 2 H2O(l) → CH4(g) + 2 O2(g) C) 6 H2O(g) + 4 CO2(g) → 2 C2H6(g) + 7 O2(g) D) H2O(l) →H2O(g) E) CO2(s) →CO2(g)
A) CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)
Which molecule has a Lewis structure that does not obey the octet rule? A) NO2 B) CS2 C) CCl4 D) PH3 E) N2O
A) NO2
Which of the elements listed below has the highest first ionization energy? A) O B) Se C) C D) P E) Ge
A) O
Which one of the following is most likely to be a covalent compound? A) SF4 B) CaCl2 C) Al2O3 D) KF E) CaSO4
A) SF4
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. Atoms are composed of protons, neutrons, and electrons.
Of the following which is NOT an example of a mixture? A. iron B. sand C. gasoline D. air E. sea water
A. iron
Which one of the following sets of quantum numbers is not possible? INCOMPLETE
B
Calculate the percent composition by mass of carbon in Na2CO3.
B) 11.3 %
Which one of the following does not represent 1.000 mol of the indicated substance? A) 12.01 g C B) 26.00 g Fe C) 65.39 g Zn D) 6.022 × 1023 Fe atoms E) 6.022 × 1023 C atoms
B) 26.00 g Fe
What type of compound is NH3?
Base
Boron obtained from borax deposits in Death Valley consists of two isotopes. They are boron-10 and boron-11 with atomic masses of 10.013 amu and 11.009 amu, respectively. The atomic mass of boron is 10.81 amu (see periodic table). Which isotope of boron is more abundant, boron-10 or boron-11?
Boron-11
An organic thiol compound is 38.66% C, 9.73% H, and 51.61% S by mass. What is the empirical formula of this compound?
C2H6S
What is the empirical formula for C6H14O?
C6H14O
The formula for calcium phosphate is
Ca3(PO4)2
Identify the reducing agent in the following chemical reaction. Cd + NiO2 + 2H2O ® Cd(OH)2 + Ni(OH)2
Cd
Which of the following ionic solids would have the largest lattice energy? A) NaF B) CaBr2 C) CsI D) SrO E) BaSO4
D) SrO
Which of the following make an isoelectronic pair: Cl-, O2-, F, Ca2+, Fe3+?
Cl- and Ca2+
What type of reaction is the following? C2H4(g) + 3 O2(g) → 2 CO2(g) + 2 H2O(g)
Combustion reaction
Arrange the following bonds in order of increasing ionic character: B—C C—N C—O C—C
C—C<B—C<C—N<C—O
Which statement is false? A) The average kinetic energies of molecules from samples of different "ideal" gases are the same at the same temperature. B) Molecules of a gas undergo many collisions with each other and the container walls. C) Molecules of greater mass have a lower average speed than those of less mass at the same temperature. D) All molecules of an ideal gas have the same kinetic energy at constant temperature. E) The molecules of an ideal gas are relatively far apart.
D) All molecules of an ideal gas have the same kinetic energy at constant temperature.
Which one of the following elements is a Lanthanide? A) Cs B) Bi C) Os D) Ce E) U
D) Ce
Predict the products of the following single replacement reaction. Ni(s) + Cu(NO3)2(aq) → A) NiCu(aq) + 2 NO3-(aq) B) NiNO3(aq) + CuNO3(aq) C) Ni(NO3)2(aq) + Cu2+(aq) D) Ni(NO3)2(aq) + Cu(s) E) No reaction occurs
D) Ni(NO3)2(aq) + Cu(s)
Which of the following is true of a compound? A. A compound must be a solid at room temperature. B. A compound is combination of two or more substances in which the substances retain their distinct identities. C. A compound must be heterogeneous. D. A compound is a substance composed of atoms of two or more elements chemicallyE. A compound is a substance that cannot be separated into simpler substances by chemical means.
D. A compound is a substance composed of atoms of two or more elements chemically
Which of these properties is/are characteristic(s) of gases? A) High compressibility B) Formation of homogeneous mixtures regardless of the nature of gases C) Relatively large distances between molecules D) AandB. E) A,B,andC.
E) A,B,andC.
Which of the following compounds is a strong acid? A) HClO2 B) H2SO3 C) HF D) HNO2 E) HI
E) HI
Which of the following compounds is a strong electrolyte? A) CH3COOH (acetic acid) B) N2 C) CH3CH2OH (ethanol) D) H2O E) KOH
E) KOH
Which of the following elements has the greatest electron affinity (largest positive value)? A) Si B) Al C) P D) Mg E) S
E) S
. The ripening of fruit is a physical change. T or F
False
20°C is colder than 40°F. T or F
False
Samples of the following volatile liquids are opened simultaneously at one end of a room. If you are standing at the opposite end of this room, which species would you smell first? (Assume that your nose is equally sensitive to all these species.) A) camphor (C10H16O) B) pentanethiol (C5H11SH) C) ethyl acetate (CH3COOC2H5) D) naphthalene (C10H8) E) diethyl ether (C2H5OC2H5)
E) diethyl ether (C2H5OC2H5)
Which of the following elements behaves chemically similarly to oxygen? A) chlorine B) beryllium C) sodium D) iron E) sulfur
E) sulfur
All of the following are properties of sodium. Which one is a physical property of sodium A. When placed in water it sizzles and a gas is formed. B. Sodium is never found as the pure metal in nature. C. It's surface turns black when first exposed to air. D. When placed in contact with chlorine it forms a compound that melts at 801°C. E. It is a solid at 25°C and changes to a liquid when heated to 98°C.
E. It is a solid at 25°C and changes to a liquid when heated to 98°C
According to the first law of thermodynamics:
Energy is neither lost nor gained in any energy transformations.
Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid. MnO2(s) + 4HCl(aq) → MnCl2(aq) + 2H2O(l) + Cl2(g) According to the above reaction, determine the limiting reactant when 5.6 moles of MnO2 are reacted with 7.5 moles of HCl.
HCl
List all types of bonding present in the compound CaCO3. I. ionic bond II. polar covalent bond III. nonpolar covalent bond
I and II
List the following sets of quantum numbers in order of increasing energy: I. n = 4, l = 0, ml = 0, ms = -1/2 II. n = 4, l = 2, ml = -1, ms = -1/2 III. n = 5, l = 0, ml = 0, ms = +1/2
I<III<II
What are the two different ions present in the compound Li3N?
Li+, N3-
Using the figure below, categorize electromagnetic radiation with a wavelength of 1.0 x 10-3 m. INCOMPLETE
Microwave
The charge on an electron was determined in the
Millikan oil drop experiment
Consider the following reaction: 3Li + Z → Li3Z. What is a reasonable guess for the identity of element Z?
N
What is the formula for dinitrogen monoxide?
N2O
Identify the major ionic species present in an aqueous solution of NH4ClO4.
NH4+, ClO4-
Arrange the following ions in order of decreasing ionic radius: Al3+, Mg2+, Na+, O2-.decreasing radius →
O2->Na+>Mg2+>Al3+
Arrange the elements F, P, and Cl in order of increasing electronegativity.
P<Cl<F
A Lewis structure of boron trifluoride is shown here. How many valence electrons are shown directly around the B atom? INCOMPLETE
Six
Boiling point is an intensive property. T or F
True
Ernest Rutherford developed the nuclear model of the atom. T or F
True
The proton is about 1840 times heavier than the electron. T or F
True
The two reactions shown here represent balanced molecular and net ionic reactions for the acid-base neutralization reaction between H3PO4(aq) and Ba(OH)2(aq). T or F Molecular equation: 2H3PO4(aq) + 3Ba(OH)2(aq) ® Ba3(PO4)2(s) + 6H2O(l) Net ionic equation: 2H3PO4(aq) + 3Ba2+(aq) + 6OH-(aq) ® Ba3(PO4)2(s) + 6H2O(l)
True
The ground-state electron configuration for an atom of indium is
[Kr]5s24d105p1.
An anion is defined as
a charged atom or group of atoms with a net negative charge.
A scientific law is
a statement describing a relationship between phenomena that is always the same
Complete this statement: Coulomb's law states that the magnitude of the force of interaction between two charged bodies is
directly proportional to the product of the charges on the bodies, and inversely proportional to the square of the distance separating them.
A possible set of quantum numbers to describe an electron in a 5p subshell is
n=5,l=1,ml=0,ms=+1/2
Which of the following is the general electron configuration for the outermost electrons of the halogens?
ns2np5
