Atomic Structure
Which of the following is the same for isotopes of an element?
A. mass number
B. mass of an atom
C. neutron number
D. atomic number
E. both atomic number and neutron number
(Question #6 on Review Packet)
D. atomic number
Which of the following statements regarding empirical formulas, molecular formulas, and percent composition is correct?
A. The compounds NO2 and N2O4 have the same empirical formula.
B. The compounds NO2 and N2O4 have the same molecular formula.
C. The empirical formula of H2O2 is H2O.
D. The empirical formula of N2O5 is NO2.5.
E. The compounds of PCl3 and PCl5 would have the same percent composition.
(Question #15 on Review Packet)
A. The compounds NO2 and N2O4 have the same empirical formula.
If the theorectical yield for a reaction is 54.9 g, and 51.3 g are actually obtained, the percent yield is:
A. 0.934%
B. 93.4%
C. 107%
D. 3.60%
E. not enough information given
(Question #26 on Review Packet)
B. 93.4%
The number of protons and neutrons in an atom of bromine-81 is:
A. 81 protons and 35 neutrons
B. 35 protons and 81 neutrons
C. 46 protons and 35 neutrons
D. 35 protons and 46 neutrons
(Question #7 on Review Packet)
D. 35 protons and 46 neutrons
Which of the following is the correct fomula for the compound with the name copper(II) sulfate?
A. Cu2S
B. CuS2
C. Cu2SO4
D. CuSO4
E. CuSO3
(Question #9 on Review Packet)
D. CuSO4
Consider the following reaction:
CrCl3(s) + KCl(s) + 2H2SO4(l) —> KCr(SO4)2(s) +4HCl(g)
green white colorless purple colorless
A. CrCl3
B. KCl
C. H2SO4
D. KCr(SO4)2
E. HCl
(Question #24 on Review Packet)
A. CrCl3
The element that has the abbreviated ground state electron configureation [Ne]3s23p2
A. Al
B. P
C. Si
D. Cl
E. Ar
(Question #29 on Review Packet)
C. Si
Which set of formulas is correct for the compounds calcium hydrogen carbonate, magnesium chloride, and calcium sulfate, which can cause scale build-up in pipes?
A. CaHCO3, MgCl2, and Ca(SO4)2
B. CaHCO3, MgCl, and Ca(SO4)2
C. Ca(HCO3)2, MgCl, and CaSO4
D. Ca(HCO3)2, MgCl2, and CaSO4
E. Ca(HCO3)2, MgCl2, and Ca2SO4
(Question #10 on Review Packet)
D. Ca(HCO3)2, MgCl2, and CaSO4
[See Picture Prompt]
Answer: D
What is the ground state electron configuration for the oxide ion?
A. 1s22s22p2
B. 1s22s22p4
C. 1s22s22p6
D. 1s22p6
E. 1s22p8
(Question #30 on Review Packet)
C. 1s22s22p6
Which of the following statements is incorrect?
A. H2SO3 has 1.5 times as many oxygen atoms as hydrogen atoms.
B. Fe2(SO4)3 has six times as many oxygen atoms as iron ions.
C. N2H4 has twice as many hydrogen atoms as nitrogen atoms.
D. MgF2 has half as many fluoride ions as magnesium ions.
E. Carbon dioxide has twice as many oxygen atoms as carbon atoms.
(Question #11 on Review Packet)
D. MgF2 has half as many fluoride ions as magnesium ions.
Rutherford's scattering experiment demonstrated
A. the existence of protons
B. the existence of electrons
C. the existence of neutrons
D. that most of the mass of an atom is in its nucleus
E. that the charge-to-mass ratio of an electron is constant
(Question #5 on Review Packet)
D. that most of the mass of an atom is in its nucleus
Which of the following observations does not relate specifically to the law of definite proportions?
A. Pure water is composed of the elements oxygen and hydrogen in a mass ratio of 8:1.
B. Any sample of a given compound always contains the same proportions by mass of the component elements.
C. The mass of the products of a chemical reaction is equal to the mass of the starting materials of the reaction.
D. When a metal reacts with oxygen, the oxygen content of the products is fixed at one or two values.
E. When water is broken down into its elements by electrolysis, elemental oxygen and hydrogen are form in an 8 to 1 mass ratio.
(Question #4 on Review Packet)
C. The mass of the products of a chemical reaction is equal to the mass of the starting materials of the reaction.
Aluminium metal reacts with sulfuric acid according to the equation:
2Al(s) +3H2SO4(aq) —> Al2(SO4)3(s) + 3H2(g)
If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al2(SO4)3 are collected, what is the percent yield for the reaction?
A. 63.4%
B. 85.5%
C. 117%
D. 47.1%
E. not enough information given
(Question #27 on Review Packet)
B. 85.5%