Download 2010 Released SOL

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts

Debye–Hückel equation wikipedia , lookup

Electrochemistry wikipedia , lookup

Click chemistry wikipedia , lookup

History of chemistry wikipedia , lookup

IUPAC nomenclature of inorganic chemistry 2005 wikipedia , lookup

Chemistry: A Volatile History wikipedia , lookup

Physical organic chemistry wikipedia , lookup

Bioorthogonal chemistry wikipedia , lookup

Hypervalent molecule wikipedia , lookup

Inorganic chemistry wikipedia , lookup

PH wikipedia , lookup

Electrolysis of water wikipedia , lookup

Stoichiometry wikipedia , lookup

Redox wikipedia , lookup

Ununennium wikipedia , lookup

Metalloprotein wikipedia , lookup

Atomic theory wikipedia , lookup

Evolution of metal ions in biological systems wikipedia , lookup

Unbinilium wikipedia , lookup

Sol–gel process wikipedia , lookup

Transcript
5/19/2015
2010 Released SOL
Name: Score: 46 / 46 points (100%)
2010 Released SOL
Multiple Response
Identify one or more choices that best complete the statement or answer the question.
Directions: Click on the correct answers.
1. According to the periodic table of the elements, which elements belong to the same period?
a. Aluminum
d. Arsenic
b. Germanium
e. Gallium
c. Antimony
RESPONSE: B,D,E
ANSWER: B,D,E
A row is known as a period, so we need all the elements in the same row.
POINTS: 1 / 1
Numeric Response
Directions: Type your answer in the box. Use “+” and “­” for the electrical charge.
2. What is the oxidation number of an oxide ion?
RESPONSE: ­2
ANSWER: ­2
or 2­
(oxide is the ionic version of oxygen and group 16 on the periodic table form
­2 ions due to the fact that this column has 6 valence electrons and need to
gain 2 more electrons. Since electrons are negative, gaining two makes a
negative 2 charge).
POINTS: 1 / 1
Directions: Type your answer in the box. Your answer must use significant digits.
3. What is the density of an aqueous solution (in g/mL) that has a mass of 10.081 g and 12.5
mL?
RESPONSE: 0.806
ANSWER: .806
or 0.806
(D=m/V; D=10.081/12.5=.80648. But we also must use sig figs according
to the directions. 10.081 has 5; 12.5 has 3 so our answer can only have 3 sig
figs)
POINTS: 1 / 1
Directions: Type your answer in the box.
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
1/17
5/19/2015
2010 Released SOL
4. Calculate the number of moles of Li3PO4 in 2.2 L of a 0.60 M Li3PO4 solution.
RESPONSE: 1.32
ANSWER: 1.32
Acceptable answers are: 1, 1., 1.3, 1.32, 1.33, 1.4, 2, or 2.
M=mol/L
0.60 = x/2.2
x= 1.32
1 / 1
POINTS: Directions: Type your answer in the box.
5. An expandable container of oxygen gas has a volume of 125 mL at a temperature of
25.0°C. What volume (in mL) will the gas occupy at 55.0°C?
RESPONSE: 137.6
ANSWER: 137.6
Acceptable answers are: 130, 130., 137, 137., 137.5, 137.6, 138, 138., 140,
or 140.
First, we need the temperature in Kelvin (+273) for this problem. Then, you
can either use the PTV trick I have shown you in class (and below) or you
can use the formula V1/T1=V2/T2.
=137.6
POINTS: 1 / 1
Directions: Click and drag the correct answers to the boxes.
Note that I am unable to have you complete these directions as stated. Instead type your
answer exactly as they would appear in the boxes.
6. Create the formula for diboron trioxide using the symbols provided.
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
2/17
5/19/2015
2010 Released SOL
RESPONSE: B2O3
ANSWER: B2O3
First elements need to start with capital letters so we have to use the B and O
for boron and oxygen. Second, the prefixes tell you how many of each you
have. di means 2 so there are 2 borons while tri means 3, so 3 oxygens. These numbers would appear in the subscript positions.
Here is the screen shot from the released
POINTS: SOL document
1 / 1
Multiple Choice
Identify the choice that best completes the statement or answers the question.
C 7. A student measures the mass of a 1.00 g aluminum rod as 0.99g. The best estimate of the
percent error associated with this measurement is ­
a. 0.01%
c. 1%
b. 0.1%
d. 10%
ANSWER: C
Percent Error = (Accepted­Experimental)/Accepted x 100
(1.00­0.99)/1.00x100=1%
POINTS: 1 / 1
B 8. The most efficient way to determine whether a reaction is an exothermic chemical reaction
is to use ­
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
3/17
5/19/2015
2010 Released SOL
a. an oxygen probe
b. a temperature probe
c. a pressure probe
d. a pH probe
ANSWER: B
exothermic reactions release heat and will feel warm/hot to the observer. As a
result, a temperature probe can be used to determine if the reaction is
increasing in temperature.
POINTS: 1 / 1
D 9. 2Al(C2H3O2)3 + 3BaSO4 Al2(SO4)3 + 3Ba(C2H3O2)2
Which type of chemical reaction does this equation represent?
a. Synthesis
c. Oxidation­reduction
b. Neutralization
d. Double replacement
ANSWER: D
Not Synthesis ­ This type of reaction results in the creation of 1 compound
from many reactants
Not Neutralization ­ This type of reaction results in an acid (starts with H) and
a base (ends with OH) making water (results from the H and OH combining)
and a salt
Not a Redox (Oxidation­reduction) because all the oxidation numbers of the
elements stay the same on the reactant and product side
It is a double replacement ­ Al and Ba switched the anion they are with.
POINTS: 1 / 1
C 10. What is the molarity of a solution with 0.2 moles of potassium permanganate (KMnO4)
dissolved in enough water to make a 500.0 mL solution?
a. 0.0004 M
c. 0.4 M
b. 0.1 M
d. 100 M
ANSWER: C
molarity is mol/L. M=0.2mol/0.500L=0.4M
(500mL ­­> L; you have to divide by 1000)
POINTS: 1 / 1
C 11. When 92.0 g of ethanol (C2H5OH) are vaporized at its boiling point of 78.3ºC, it requires
78.6 kJ of energy. What is the approximate molar heat of vaporization of ethanol in
kJ/mol?
a. 0.854
c. 39.3
b. 1.17
d. 78.3
ANSWER: C
The told you that you need kJ/mol, so divide the kJ by moles. (Note:
temperature doesn’t play a part in molar heat of vaporization because heat
equals moles times molar heat of vaporization)
So, turn the grams to moles 92.0g x (
)=2 mol
78.6kJ/2mol = 39.3
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
4/17
5/19/2015
2010 Released SOL
POINTS: 1 / 1
B 12. Which element has 16 neutrons, 15 protons, and 15 electrons?
a. Sulfur (S)
c. Gallium (Ga)
b. Phosphorus (P)
d. Zinc (Zn)
ANSWER: B
The important subatomic particle here is the proton. The number of protons =
atomic number, which tells you the element is phosphorus (atomic number 15).
POINTS: 1 / 1
A 13. Al(s) + 3AgNO3(aq) Al(NO3)3(aq) + 3Ag(s)
This equation represents which type of chemical reaction?
a. Single­replacement
c. Decomposition
b. Double­replacement
d. Synthesis
ANSWER: A
Single­replacement ­ element + compound ­­> element + compound Yes
Double­replacement ­ compound + compound ­­> compound + compound No
Decomposition ­ 1 substance breaks down to 2 or more No
Synthesis ­ 2 or more substance combine to make 1 No
POINTS: 1 / 1
C 14. In the formula for barium chloride, (BaCl2), barium (Ba) is written first because it is ­
a. a single atom
c. the positive ion
b. a larger ion
d. the negative ion
ANSWER: C
When writing a chemical formula, the first ion is positive (the cation) and the
second is negative (anion)
POINTS: 1 / 1
C 15. Which of these laboratory techniques is best to separate a solid from a liquid to recover the
liquid?
a. Titration
c. Filtering
b. Chromatography
d. Vaporization
ANSWER: C
Titration ­ experiment usually with acids and bases that is used to determine
the concentration of an unknown substance No
Chromatography ­ uses a mobile and stationary phase to separate a mixture of
various types of phases, but it usually separates gases from gases or liquids
from liquids Not the best choice
Filtering ­ separates the liquid and the solid. The solid would get stuck in the
filter and the liquid is collected in another container Yes
Vaporization ­ separates a liquid and a solid by the liquid would escape as it
evaporated No
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
5/17
5/19/2015
2010 Released SOL
POINTS: 1 / 1
A 16. Which of these is NOT required to ensure that stock solutions are free of contamination?
a. Store all solutions in brown bottles
b. Do not place dropping pipettes in stock solution bottles
c. Never return excess chemicals to stock bottles
d. Replace tops on reagent bottles after use
ANSWER: A
Store all solutions in brown bottles ­ Colored bottles can help some substances
from breaking down, but it is not required to keep contaminants out of the
bottle Yes
Do not place dropping pipettes in stock solution bottles ­ any contaminant on
the pipette would get into the solution and cause contamination No
Never return excess chemicals to stock bottles ­ any contaminant on the excess
chemicals would get into the solution and cause contamination No
Replace tops on reagent bottles after use ­ this would prevent contaminants
from falling into the bottle No
POINTS: 1 / 1
D 17. Which of these values is most responsible for changing the boiling and freezing points of a
solvent?
a. Molar mass of the solvent
c. Weight of the solute particles
b. Electronegativity of the solvent
d. Number of solute particles
ANSWER: D
Colligative properties like boiling point elevation and freezing point depression
depend on the concentration of the solute in the solvent in molality, so it would
be the number of dissolved particles
POINTS: 1 / 1
A 18. What is the name of the compound with the formula NH4NO3?
a. Ammonium nitrate
c. Nitrogen hydrogen oxide
b. Nitrogen nitrate
d. Ammonium nitrogen trioxide
B 19. ANSWER: A
NH4+ is known as ammonium and NO3­ is called nitrate
POINTS: 1 / 1
N2(g) + 3F2(g) 2NF3(g)
Equilibrium has been reached for the reaction shown. Which conclusion is correct?
a. The N2 and F2 together will form at a faster rate than the NF3.
b. The partial pressures of N2, F2, and NF3 will stay constant.
c. The NF3 will form at a faster rate than the N2 and F2 together.
d. The partial pressure of NF3 will keeping changing.
ANSWER: B
Equilibrium is when the forward and reverse rate are equal. With this in mind
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
6/17
5/19/2015
A 2010 Released SOL
choice a and c could not be the answer. And according to Le Chatelier’s
principle, changing the pressure of a system would add stress that would result
in the equilibrium to shift. As a result, d would not be an option because this
would mean that it wouldn’t be in equilibrium. b would have to be the answer
because the equal rates would keep the pressures constant.
POINTS: 1 / 1
20. If 89.6 joules of heat are needed to heat 20.0 grams of iron from 30.0°C to 40.0°C, what is
the specific heat of the iron in ?
a. 0.448
b. 2.23
c. 8.96
d. 896
ANSWER: A
q=mcpT
89.6=(20)(x)(40­30)
89.6=200x
x=89.6/200=0.448
or, they said they wanted the answer in their spots , so if we plug the numbers in
= 0.448
POINTS: 1 / 1
B 21. Which of the four substances on this pH scale is slightly basic?
a. Calcium hydroxide
b. Human blood
c. Whole milk
d. Lemon juice
ANSWER: B
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
7/17
5/19/2015
2010 Released SOL
A pH of 7 is neutral
less than 7 is an acid
greater than 7 is a base
We want the option that is slightly greater than 7
POINTS: 1 / 1
A 22. Which element will most likely form covalent bonds with fluorine?
a. Carbon
c. Neon
b. Potassium
d. Tin
ANSWER: A
Covalent bonds are between 2 nonmetals (ionic would have a metal and
nonmetal)
Fluorine is a nonmetal so we need another nonmetal
carbon is a nonmetal yes
potassium is a metal no
neon is a nonmetal, but it is also a noble gas. Therefore it is extremely stable
and does not react to make compounds no
tin is a metal no
POINTS: 1 / 1
D 23. The physical process of evaporation involves ­
a. ion formation
c. transferring valence electrons
b. electron sharing
d. overcoming intermolecular forces
C 24. ANSWER: D
For something to evaporate, the molecules have to have enough energy to get
away from each other and overcome any attraction they have with each other. inter­ means between so intermolecular forces are the forces between the
molecules. This is what needs to be broken.
POINTS: 1 / 1
___ C2H4 + _?_O2 ___CO2 + ___ H2O
How many moles of O2 are in the chemical equation when balanced using the lowest whole
numbers?
a. 5
b. 4
c. 3
d. 2
B 25. ANSWER: C
When the equation is balanced, we would have the coefficients (and therefore
relative moles) of:
_1_ C2H4 + _3_O2 _2_CO2 + _2_ H2O
POINTS: 1 / 1
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
8/17
5/19/2015
2010 Released SOL
While English physicist J.J. Thomson was carrying out experiments on cathode rays, he
was able to determine that the rays consisted of particles he classed “corpuscles.” These
particles were later names­
a. protons
c. gamma rays
b. electrons
d. neutrons
ANSWER: B
J.J. Thomson discovered the electron using the cathode ray experiment; plus
the diagram shows the particle leaving the negative side and being attracted to
the positive anode. Since electrons a negative, it can be concluded that the
particle is the electron.
POINTS: 1 / 1
D 26. In the Haber process, nitrogen (N2) and hydrogen (H2) are directly combined to form
ammonia (NH3). Which illustration contains the stoichiometric quantities of the reactants
for this reaction?
a.
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
c.
9/17
5/19/2015
2010 Released SOL
b.
d.
ANSWER: D
For every N, we need 3 H (NH3). The illustration that shows this ratio is because 4:12 reduces to 1:3
POINTS: 1 / 1
C 27. A beaker of water is placed in a large sealed jar that is attached to a vacuum pump. As air
is pumped out of the jar, the water begins to boil because ­
a. the temperature of the water decreases as the surrounding pressure decreases
b. the lower pressure inside the jar causes the water to contract
c. the air pressure in the jar has been lowered until it is equal to the vapor pressure of
the water
d. the pressure on the water is insufficient to hold the hydrogen and oxygen atoms
together, resulting in a decomposition reaction
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
10/17
5/19/2015
2010 Released SOL
ANSWER: C
To evaporate, the water molecules have to be able to get away from each
other. However, at normal pressure, the water molecules that try to leave run
into air molecules that knock them back into the liquid in the beaker. As the
pump removes the air molecules, the water molecules can start to escape. So,
choice c is the option that describes this the best.
POINTS: 1 / 1
B 28. How many moles are in 2.04 x 1024 molecules of H2O?
a. 0.295 mol
b. 3.39 mol
c. 1.13 x 1024 mol
d. 1.44 x 1048 mol
ANSWER: B
uses Avogadro’s Number:
2.04 x 1024 molecules x =3.3887
POINTS: 1 / 1
D 29. What is the name for FeCl3 using the IUPAC nomenclature rules?
a. Iron chloride
c. Iron trichloride
b. Iron (II) chloride
d. Iron (III) chloride
ANSWER: D
IUPAC stands for The International Union of Pure and Applied Chemistry and
is the current way for naming compounds. In this case, you would have to
realize that Fe is a metal, therefore you have an ionic compound. Ionic
compounds don’t use prefixes so Iron trichloride is out as a choice. Next, we
have to see that iron is a transition element (metal) with more than one
oxidation number, so a roman numeral is needed (eliminates Iron chloride). Since the oxidation of the Fe in this compound is +3 (+3x1Fe = ­1x3Cl), the
roman numeral needs to be a 3 to match this charge.
POINTS: 1 / 1
C 30. Which of these correctly describes how organic catalysts operate in biological reactions?
a. They are used up in the reactions.
b. They lower the overall energy of the reactions.
c. They lower the activation energy of the reactions.
d. They keep the temperature of the reactions constant.
ANSWER: C
Catalyst speed up the reaction by lowering the activation energy.
POINTS: 1 / 1
A 31. What volume will 35.9 g of hydrogen gas (H2) occupy at STP?
a. 399 L
c. 804 L
b. 798 L
d. 1,620 L
ANSWER: A
STP means standard temperature and pressure, which means you can use 22.4
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
11/17
5/19/2015
2010 Released SOL
L/mol
In this problem, we are going to have to change the grams of H2 to moles using
the molar mass of H2 and then change those moles to L using the 22.4. Note:
they used the entire atomic mass of H to get the answer. If you used 1.0 for
hydrogen and got an answer of 402, you would have to notice that 399L is the
closest answer and the difference is the rounding.
35.9g x B 32. x
=398.91
H­­>1.00794x2=2.01588
POINTS: 1 / 1
___ Ca(NO3)2 + _?_H3PO4 ___Ca3(PO4)2 + ___ HNO3
When this equation is balanced, the coefficient in front of H3PO4 is ­
a. 1
b. 2
c. 3
d. 4
ANSWER: B
When the equation is balanced, we would have the coefficients of:
_3_ Ca(NO3)2 + _2_H3PO4 _1_Ca3(PO4)2 + _6_ HNO3
POINTS: 1 / 1
D 33. Increasing the volume of a sealed container will cause the gas particles within the container
to ­
a. form a liquid
c. increase in molecular attraction
b. collide more frequently
d. exhibit lower pressure
ANSWER: D
By increasing the volume, you are giving the molecules more room, therefore:
form a liquid ­ incorrect, you would have to force the gas particles together to
make them turn into a liquid
collide more frequently ­ incorrect, you gave them more room so they will
collide less frequently
increase in molecular attraction ­ incorrect, you gave them more space so they
will have less opportunity to be attracted to each other
exhibit lower pressure ­ correct, and this follows Boyle’s law, as volume
increases, pressure decreases
POINTS: 1 / 1
D 34. Melting Point Results (°C)
Trial
Group 1
Group 2
Group 3
Group 4
1
113
114
116
110
2
111
115
113
111
3
110
111
114
111
4
110
110
113
110
Each of four groups of students determine and recorded the melting point of a solid
compound. If the actual melting point is 113°C, which group has the best precision?
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
12/17
5/19/2015
2010 Released SOL
a. Group 1
b. Group 2
c. Group 3
d. Group 4
ANSWER: D
Precision is how close your numbers are to each other, so the 113°C is
irrelevant to this problem. (It would only be used for accuracy; how close the
group is to the correct answer). Plus, make sure you are reading down the
columns for each group. But the group with the most consistent (or precise)
numbers is Group 4 with 110, 111, 111, and 110.
POINTS: 1 / 1
A 35. Consider any set of three elements in the same period on the periodic table. For which
characteristics is the average for the three elements always equal to the value of the middle
element?
a. Atomic number
c. Number of neutrons
b. Atomic mass
d. Number of isotopes
ANSWER: A
Since atomic number always increases by 1 as you increase elements, this is
the only characteristic that is listed that is consistent enough to have the
average work.
POINTS: 1 / 1
B 36. A substance has a molecular formula of C8H10N4O2. The empirical formula is ­
a. C2H6N2O
c. C9H7N3O
b. C4H5N2O
d. CHNO
ANSWER: B
The empirical formula is the simplified ratio of all the atoms in a compound. Since all the numbers in the molecular formula can be divided by 2, it would
become C4H5N2O.
POINTS: 1 / 1
D 37. What is the name for the compound AlI3?
a. Aluminum (I) iodide
c. Aluminum (III) iodide
b. Aluminum triiodide
d. Aluminum iodide
ANSWER: D
In this case, you would have to realize that Al is a metal, therefore you have an
ionic compound. Ionic compounds don’t use prefixes so Aluminum triiodide
is out as a choice. Next, we have to see that aluminum is a metal with only one
oxidation number (+3), so a roman numeral is NOT needed (eliminates
Aluminum (I) iodide and Aluminum (III) iodide).
POINTS: 1 / 1
B 38. 2C4H10 + 13O2 8CO2 + 10H2O
How many moles of carbon dioxide (CO2) are produced when reacting 6.00 moles of
butane (C4H10) in excess oxygen (O2)?
a. 1.50 mol
c. 66.0 mol
b. 24.0 mol
d. 1,060 mol
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
13/17
5/19/2015
2010 Released SOL
ANSWER: B
Excess oxygen means we have extra O2 and therefore do not need to worry
about it in this problem. So, we need to change moles of C4H10 to moles of
CO2. In class we talked about how to recognize how many steps you will need
in your stoichiometry problem. Since they gave us moles and asked for moles,
we don’t need the first or last step. We only need the step to switch the
compounds (mole ratio step using the coefficients in the balanced equation)
6.00 mol C4H10 x = 24.0 mol CO2
The other way to think of this problem is that coefficients equal relative
moles. So, if we are tripling the number of moles of butane (2­­>6), then we
have to triple the amount of carbon dioxide (8x3=24)
POINTS: 1 / 1
A 39. Which structure represents a nonpolar molecule?
a.
c.
b.
d.
ANSWER: A
To be nonpolar, the molecule has to be symmetrical. The only symmetrical molecule is a.
b is not symmetrical due to the alcohol group (OH) being different from the
rest of the Hs
c is not symmetrical due to the Cl being different from the Hs
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
14/17
5/19/2015
2010 Released SOL
d is not symmetrical due to the O being different from the Hs
POINTS: 1 / 1
C 40. Using only one trial to collect data in an experiment ­
a. makes it easier to determine a valid conclusion
b. reduces the percent error in the results
c. causes the conclusion to be less reliable
d. requires data with more significant figures
ANSWER: C
Only having one trial is NOT advised because one cannot compare the results
to see if any sources of error occurred during the trial. As a result, the data and
the results cannot be truly trusted, thus making the conclusion less reliable.
POINTS: 1 / 1
B 41. A common product of acid­base neutralization reactions is ­
a. hydrogen
c. carbon dioxide
b. water
d. oxygen
D 42. ANSWER: B
During a neutralization reaction, an acid (tends to start with H) and a base
(tends to end with OH) react to form water (results from the H and OH coming
together) and a salt.
POINTS: 1 / 1
Solution
NaHCO3
HClO
NaNO3
CH3NH2
Data Table
Brightness of Light
Bulb
Bright
Dim
Bright
Dim
pH
8.4
3.7
7.0
8.0
Based on the information provided, which solution is a base and a weak electrolyte?
a. NaHCO3
c. NaNO3
b. HClO
d. CH3NH2
ANSWER: D
A weak electrolyte would make the light bulb glow dimly (strong electrolytes
would make it bright). A base has a pH greater than 7. So we need to look for
something that is dim and a pH>7.
POINTS: 1 / 1
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
15/17
5/19/2015
B 43. 2010 Released SOL
What is the half­life of Americium­242?
a. 11 hours
b. 16 hours
A 44. c. 32 hours
d. 64 hours
ANSWER: B
A half­life is the amount of time required to lose half of your material. According to the graph, it takes 16 hours to go from 80 to 40.
POINTS: 1 / 1
Two electrons are shared equally in bromine (Br2). What type of bond is represented
between the bromine atoms in this Lewis structure?
a. Nonpolar covalent bond
c. Metallic bond
b. Polar covalent bond
d. Ionic bond
ANSWER: A
Since Br is a nonmetal and we have a compound between two nonmetals, we
have a covalent bond. (Ionic would be between a metal and nonmetal and
metal is between two metals). And because the electrons are being shared
equally, it would be a nonpolar covalent bond.
POINTS: 1 / 1
A 45. A student is studying the effects of several solutions on the prevention of the browning of
apples. The student used solutions having different pH values and immersed three apple
slices in equal volumes of the solutions. Which of these is the independent variable in this
investigation?
a. pH of solution
c. Number of apple slices
b. Shade of brown
d. Volume of solutions
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
16/17
5/19/2015
2010 Released SOL
ANSWER: A
I
The ndependent variable is what the scientist changes (put yourself in the
I
position of the scientist and ask what did change). In this case, I changed the
pH of the solution. Other part of the experiment review:
(The dependent variable is what changes because of the independent variable. In this case the shade of the apple changes because of the pH of the solution. Constants stay the same throughout the experiment; the number of apples and
volume of solution are constants. And a control is what we can set up to
compare our results to and is usually lacking the independent variable. In this
case, if we had an apple not in a solution or maybe a pH of 7 (neutral); that
would most likely be our control).
POINTS: 1 / 1
D 46. An experiment produced 0.10 g CO2 with a volume of 0.056 L at STP. If the accepted
density of CO2 at STP is 1.96 g/L, what is the approximate percent error?
a. 110%
c. 71%
b. 92%
d. 8.2%
ANSWER: D
First, we need to determine the experimental density by solving D=m/V.
D = 0.10g/0.056L = 1.8 g/L
Then, we need to calculate % error by solving (accepted­
experimental)/accepted x 100
x100 = 8.2%
POINTS: 1 / 1
file:///F:/SOL%20Review%20Topics/Chemistry%202010%20SOL/2010_released_sol.htm
17/17