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Worksheets50 Most Commonly Missed Questions
Total questions: 50
Worksheet time: 25mins
In the wave-mechanical model, an orbital is a region of space in an atom where there is
(1) a high probability of finding an electron
(2) a high probability of finding a neutron
(3) a circular path in which electrons are found
(4) a circular path in which neutrons are found
What is the charge of the nucleus in an atom of oxygen-17?
0
-2
+8
+17
Helium is most likely to behave as an ideal gas when it is under
(1) high pressure and high temperature
(2) high pressure and low temperature
(3) low pressure and high temperature
(4) low pressure and low temperature
At STP, the element oxygen can exist as either O2 or O3 gas molecules. These two forms of the element have
(1) the same chemical and physical properties
(2) the same chemical properties and different physical properties
(3) different chemical properties and the same physical properties
(4) different chemical and physical properties
In a nuclear fusion reaction, the mass of the products is
(1) less than the mass of the reactants because some of the mass has been converted to energy.
(2) less than the mass of the reactants because some of the energy has been converted to mass.
(3) more than the mass of the reactants because some of the mass has been converted to energy.
(4) more than the mass of the reactants because some of the energy has been converted to mass.
Which pair of formulas represents two compounds that are electrolytes?
(1) HCl and CH3OH
(2) HCl and NaOH
(3) C5H12 and CH3OH
(4) C5H12 and NaOH
Which compound could serve as a reactant in neutralization reaction?
(1) NaCl
(2) KOH
(3) CH3OH
(4) CH3CHO
How many electrons are contained in an Au3+ ion?
76
79
82
197
Which type of molecule is CF4?
(1) polar, with a symmetrical distribution of charge
(2) polar, with an asymmetrical distribution of charge
(3) nonpolar, with a symmetrical distribution of charge
(4) nonpolar, with an asymmetrical distribution of charge
Conductivity in a metal results from the metal atoms having
(1) high electronegativity
(2) high ionization energy
(3) highly mobile protons in the nucleus
(4) highly mobile electrons in the valence shell
Which of these elements has the greatest attraction for electrons in a chemical bond?
Oxygen
Fluorine
Nitrogen
Chlorine
Given the reaction for the corrosion of aluminum: 4Al + 3O2 → 2Al2O3 Which half-reaction correctly represents the oxidation that occurs?
(1) Al° + 3e−1 → Al3+
(2) Al° → Al3+ + 3e−1
(3) O2° + 4e−1 → 2O2−
(4) O2° → 2O2− + 4e−1
Given the reaction in the image below; what is it an example of:
fermentation
saponification
hydrogenation
esterfication
Systems in nature tend to undergo changes toward
(1) lower energy and lower entropy
(2) lower energy and higher entropy
(3) higher energy and lower entropy
(4) higher energy and higher entropy
Which molecule contains a polar covalent bond?
O=C=O
Br-Br
CO
CCl4
Which equation represents a fusion reaction?
(1) H2O(G) → H2O(L)
(2) C(S) + O2(G) → CO2(G)
(3) 21H + 31H →42He + 10n
(4) 23592U + 10n → 14256Ba + 9136Kr + 310n
Compared to a 0.1 M aqueous solution of NaCl, an 0.8 M aqueous solution of NaCl has a
(1) higher boiling point and a higher freezing point
(2) higher boiling point and a lower freezing point
(3) lower boiling point and a higher freezing point
(4) lower boiling point and a lower freezing point
The kinetic molecular theory assumes that the particles of an ideal gas
(1) are in random, constant, straight-line motion
(2) are arranged in a regular geometric pattern
(3) have strong attractive forces between them
(4) have collisions that result in the system lowering energy
At STP, solid carbon can exist as graphite or as diamond. These two forms of carbon have
(1) the same properties and the same crystal structures
(2) the same properties and different crystal structures
(3) different properties and the same crystal structures
(4) different properties and different crystal structures
According to Reference Table G, which substance forms an unsaturated solution when 80 grams of the substance is dissolved in 100 grams of H2O at 10oC?
KI
KNO3
NaNO3
NaCl
Where does oxidation occur in an electrochemical cell?
(1) at the cathode in both an electrolytic and a voltaic cell
(2) at the cathode in an electrolytic cell and at the anode in a voltaic cell
(3) at the anode in both an electrolytic cell and a voltaic cell
(4) at the anode in an electrolytic cell and at the cathode in a voltaic cell
What is the formula of titanium(II) oxide?
TiO
TiO2
Ti2O
Ti2O3
A 1.0-gram piece of zinc reacts with 5 milliliters of HCl(aq). Which of these conditions of concentration and temperature would produce the greatest rate of reaction?
(1) 1.0 M HCl(aq) at 20 oC
(2) 1.0 M HCl(aq) at 40 oC
(3) 2.0 M HCl(aq) at 20 oC
(4) 2.0 M HCl(aq) at 40 oC
Which equation represents a transmutation reaction?
(1) 23992U → 23992U + 00γ
(2) 146C → 147N + 0−1e
(3) C3H8 + 5 O2 → 3 CO2 + 4 H2O
(4) n C2H4 → (―C2H4―)n
Given the balanced ionic equation: Zn(s) + Cu2+(aq) → Zn2+(aq) + Cu(s) Which equation represents the oxidation half-reaction?
(1) Zn(s) + 2e− → Zn2+ (AQ)
(2) Zn(s) → Zn2+ (AQ) + 2e−
(3) Cu2+ (AQ) → Cu°(s) + 2e−
(4) Cu2+ (AQ) + 2e− → Cu°(s)
As a chlorine atom becomes a negative ion, the atom
(1) gains an electron and its radius increases
(2) gains an electron and its radius decreases
(3) loses an electron and its radius increases
(4) loses an electron and its radius decreases
Which symbol represents a particle that has the same total number of electrons as S2−?
(1) O2−
(2) Si
(3) Se2−
(4) Ar
Given the reaction in the image below which statement best describes this process?
(1) It is endothermic and entropy increases
(2) It is endothermic and entropy decreases
(3) It is exothermic and entropy increases
(4) It is exothermic and entropy decreases
Atoms of different isotopes of the same element differ in their total number of
electrons
neutrons
protons
valance electrons
Which balanced equation represents a redox reaction?
(1) AgNO3 + NaCl → AgCl + NaNO3
(2) BaCl2 + K2CO3 → BaCO3 + 2KCl
(3) CuO + CO → Cu + CO2
(4) HCl + KOH → KCl + H2O
A saturated solution of NaNO3 is prepared at 60.oC using 100. grams of water. As this solution is cooled to 10.oC, NaNO3 precipitates (settles) out of the solution. The resulting solution is saturated. Approximately how many grams of NaNO3 settled out of the original solution?
46 g
61 g
85 g
126 g
What is the IUPAC name for the compound that has the condensed structural formula CH3CH2CH2CHO?
butanal
butanol
propanal
propanol
. A student tested a 0.1 M aqueous solution and made the following observations: Conducts electricity. Turns blue litmus red. Reacts with Zn(S) to produce gas bubbles. Which compound could be the solute in this solution?
CH3OH
LiBr
HBr
LiOH
What is the half-life of sodium-25 if 1.00 grams of a 16.00-gram sample of sodium-25 remains unchanged after 237 seconds?
47.4 seconds
59.3 seconds
79.0 seconds
118 seconds
Given the table below that shows students' examples of proposed models of the atom: Which model correctly describes the locations of protons and electrons in the wave mechanical model?
A
B
C
D
Which reactants form the salt CaSO4(s) in a neutralization reaction?
(1) H2S(G) and Ca(ClO4)2(S)
(2) H2SO3(AQ) and Ca(NO3)2(AQ)
(3) H2SO4(AQ) and Ca(OH)2(AQ)
(4) SO2(G) and CaO(S)
A metal, M forms an oxide compound with the general formula M2O. In which group on the Periodic Table could metal M be found?
Group 1
Group 2
Group 16
Group 17
What volume of 0.500 M HNO3(AQ) must completely react to neutralize 100.0 milliliters of 0.100 M KOH(AQ)
10.0 mL
20.0 mL
50.0 mL
500.0 mL
Given the balanced equation with an unknown compound represented by X: C6H12O6(AQ) → 2 X + 2 CO2(G) Which compound is represented by X ?
CH3OH
CH3CH2OH
CH2(OH)4
CH2OHCH2OH
Which statement correctly describes the 2 forms of oxygen, O2 & O3?
(1) They have identical molecular structures and identical properties.
(2) They have identical molecular structures and different properties.
(3) They have different molecular structures and identical properties.
(4) They have different molecular structures and different properties.
What is the total number of electrons shared in the bonds between the two carbon atoms in a molecule of H―C≡C―H?
6
3
2
8
Which changes occur as a cadmium atom, Cd, becomes a cadmium ion, Cd2+?
(1) The Cd atom gains two electrons and its radius decreases.
(2) The Cd atom gains two electrons and its radius increases.
(3) The Cd atom loses two electrons and its radius decreases.
(4) The Cd atom loses two electrons and its radius increases.
The compounds CH3OCH3 and CH3CH2OH are isomers of each other. These two compounds must have the same
density
reactivity
melting point
molecular formula
Which process occur at the anode in an electrochemical cell?
the loss of protons
the loss of electrons
the gain of electrons
the gain of protons
Which substance is an electrolyte?
CH3OH
C6H12O6
H2O
KOH
Which ion is the only negative ion present in an aqueous solution of an Arrhenius base?
hydride ion
hydrogen ion
hydroxide ion
hydronium ion
A dilute, aqueous potassium nitrate solution is best qualified as a
(1) homogeneous compound
(2) homogeneous mixture
(3) heterogeneous compound
(4) heterogeneous mixture
For a given reaction, adding a catalyst increases the rate of the reaction by
(1) providing an alternate reaction pathway that has a higher activation energy
(2) providing an alternate reaction pathway that has a lower activation energy
(3) using the same reaction pathway and increasing the activation energy
(4) using the same reaction pathway and decreasing the activation energy
What is the total charge on the nucleus of a carbon atom?
-6
0
+6
+12
Which radioisotope is used in medicine to treat thyroid disorders?
cobalt 60
iodine 131
phosphorus 32
uranium 238
