SAT Chemistry Subject Test - Practice Test 3

SAT Chemistry Subject Test - Practice Test 3

Note: For all questions involving solutions and/or chemical equations, assume that the system is in water unless otherwise stated.
Reminder: You may not use a calculator on these tests.
The following symbols have the meanings listed unless otherwise noted.
H = enthalpy
M = molar
n = number of moles
P = pressure
R = molar gas constant
S = entropy
T = temperature
V = volume
atm = atmosphere
g = gram(s)
J = joules(s)
kj = kilojoules
L = liter(s)
mL = milliliter(s)
mm = millimeter(s)
mol = mole(s)
V = volt(s)
PART A

Directions: Every set of the given lettered choices below refers to the numbered statements or formulas immediately following it. Choose the one lettered choice that best fits each statement or formula and then fill in the corresponding oval on the answer sheet. Each choice may be used once, more than once, or not at all in each set.

Questions 1-4:
refer to the following diagram:
sat-physics-subject-test-practice-test-3-373-1
1. The activation energy of the forward reaction is shown by
2. The activation energy of the reverse reaction is shown by
3. The heat of the reaction for the forward reaction is shown by
4. The potential energy of the reactants is shown by

Questions 5-7:
refer to the following diagram and information:
sat-physics-subject-test-practice-test-3-374-1
When a strip of aluminum is placed in a solution of copper(II) chloride, a reaction takes place. As time goes by, a brown solid forms on the strip of alumi­num and the blue solution turns clearer.

5. One product of the reaction would be
(A) AlCl2
(B) AlCl3
(C) AlCl4
(D) CuAl3
(E) CuAl2

6. The aluminum is
(A) being deprotonated
(B) being disproportionated
(C) being reduced
(D) being oxidized
(E) gaining mass

7. The copper(II) ion concentration in solution
(A) is zero at the beginning of the reaction
(B) has no effect on the rate of the reaction
(C) stays the same and doesn’t influence the color of the solution
(D) increases, making the solution less blue
(E) decreases, making the solution less blue

Questions 8-11:
match the following equations to the appropriate descriptions:
(A) V/T = k
(B) P/T = k
(C) PV = k
(D) PT = P1+ P2+ P3
(E) PT = k

8. This equation shows the volume decreasing as the pressure is increased when the temperature is held constant. It is an example of Boyle’s Law.

9. This equation shows the pressure increasing as the temperature is increased when the volume is held constant. It is an example of Gay-Lussac’s Law.

10. This equation shows the volume increasing as the temperature is increased when the pressure is held constant. It is an example of Charles’s Law.

11. This equation shows that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases.

Questions 12-14:
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

12. When the following reaction equation is balanced, what will be the coefficient of the NaNO3 using the smallest whole number?
Nal(aq) + Pb(NO3)2(aq) → NaNO3(aq) + Pbl2(s)

13. If 0.5 moles of Pbl2 formed according to the balanced equation from question 12, how many moles of Nal were needed to make it?

14. If NaNO3 goes into solution as ions, into how many ions would it dissociate?

Questions 15-18:
(A) Ionic substance
(B) Polar covalent substance
(C) Nonpolar covalent substance
(D) Amorphous substance
(E) Metallic network

15. MgCl2(s)
16. HCl(g)
17. CH3-CH3(g)
18. Cu(s)

Questions 19-23:
(A) Dissociation
(B) Amphoteric
(C) Phenolphthalein
(D) Dehydration
(E) Deliquescence

19. The reason why a blue crystal of CuSO4 5H2O turns white when heated
20. The reason why ionic substances dissolved in water exhibit conductivity
21. The reason there may be a pink color in a basic solution
22. The reason why a substance may act like an acid or like a base depending on the substance it is in the presence of
23. The reason why an ionic solid may dissolve in the moisture it absorbs from the air

PART B

ON THE ACTUAL CHEMISTRY TEST, THE FOLLOWING TYPE OF QUESTION MUST BE ANSWERED ON A SPECIAL SECTION (LABELED “CHEMISTRY”) AT THE LOWER LEFT-HAND CORNER OF PAGE 2 OF YOUR ANSWER SHEET. THESE QUESTIONS WILL BE NUMBERED BEGINNING WITH 101 AND MUST BE ANSWERED ACCORDING TO THE FOLLOWING DIRECTIONS.

Directions: Every question below contains two statements, I in the left-hand column and II in the right-hand column. For each question, decide if statement I is true or false and if statement II is true or false and fill in the corresponding T or F ovals on your answer sheet. *Fill in oval CE only if statement II is a correct explanation of statement I.

Sample Answer Grid:
CHEMISTRY * Fill in oval CE only if II is a correct explanation of I.
sat-physics-subject-test-practice-test-3-375-1
sat-physics-subject-test-practice-test-3-376-1
sat-physics-subject-test-practice-test-3-376-2
sat-physics-subject-test-practice-test-3-377-1

PART C

Directions: Every question or incomplete statement below is followed by five suggested answers or completions. Choose the one that is best in each case and then fill in the corresponding oval on the answer sheet.

Questions 24:
What are the simplest whole-number coefficients that balance this equation?
... C4H10 + ... O2 → ... CO2 + ... H2O
(A) 1,6, 4,2
(B) 2, 13, 8, 10
(C) 1, 6, 1, 5
(D) 3, 10, 16, 20
(E) 4, 26, 16, 20

Questions 25:
How many atoms are present in the formula KAl(SO4)2?
(A) 7
(B) 9
(C) 11
(D) 12
(E) 13

Questions 26:
All of the following are compounds EXCEPT
(A) copper sulfate
(B) carbon dioxide
(C) washing soda
(D) air
(E) lime

Questions 27:
What volume of gas, in liters, would 2.0 moles of hydrogen occupy at STP?
(A) 2
(B) 4
(C) 6
(D) 8
(E) 2

Questions 28:
What is the maximum number of electrons held in the d orbitals?
(A) 2
(B) 6
(C) 8
(D) 10
(E) 14

Questions 29:
If an element has an atomic number of 11, it will combine most readily with an element that has an electron configuration of
sat-physics-subject-test-practice-test-3-377-29

Questions 30:
An example of a physical property is
(A) rusting
(B) decay
(C) souring
(D) low melting point
(E) high heat of formation

Questions 31:
A gas at STP that contains 6.02 × 1023 atoms and forms diatomic molecules will occupy
(A) 11.2 L
(B) 22.4 L
(C) 33.6 L
(D) 67.2 L
(E) 1.06 qt

Questions 32:
When excited electrons cascade to lower energy levels in an atom,
(A) visible light is always emitted
(B) the potential energy of the atom increases
(C) the electrons always fall back to the first energy level
(D) the electrons fall indiscriminately to all levels
(E) the electrons fall back to a lower unfilled energy level

Questions 33:
Mass spectroscopy uses the concept that
(A) charged particles are evenly deflected in a magnetic field
(B) charged particles are deflected in a magnetic field inversely to the mass of the particles
(C) particles of heavier mass are deflected in a magnetic field to a greater degree than lighter particles
(D) particles are evenly deflected in a magnetic field

Questions 34:
The bond that describes an interaction between two orbitals that is not symmetrical about a line between the two atoms’ nuclei is called
(A) a pi bond
(B) a sigma bond
(C) a hydrogen bond
(D) a covalent bond
(E) an ionic bond

Questions 35:
What is the boiling point of water at the top of Pikes Peak? (Note: Pikes Peak is well above sea level.)
(A) It is 100°C.
(B) It is >100°C since the pressure is less than at ground level.
(C) It is <100°C since the pressure is less than at ground level.
(D) It is >100°C since the pressure is greater than at ground level.
(E) It is <100°C since the pressure is greater than at ground level.

Questions 36:
The atomic structure of the alkane series contains the hybrid orbitals designated as
(A) sp
(B) sp2
(C) sp3
(D) sp3d2
(E) sp4d3

Questions 37:
Which of the following is (are) true for this reaction?
Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2(g)
I. It is an oxidation-reduction reaction.
II. Copper is oxidized.
III. The oxidation number of nitrogen goes from +5 to +4.
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III

Questions 38:
Which of the following properties can be attributed to water?
I. It has a permanent dipole moment attributed to its molecular structure.
II. It is a very good conductor of electricity.
III. It has its polar covalent bonds with hydrogen on opposite sides of the oxygen atom, so that the molecule is linear.
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III

Questions 39:
All of the following statements are true for this reaction EXCEPT
HCl(g) + H2 O(l) → H3O+(aq) +Cl-(aq)
(A) H3O+ is the conjugate acid of H2
(B) CP is the conjugate base of HCl.
(C) H2O is behaving as a Bronsted-Lowry base.
(D) HCl is a weaker Bronsted-Lowry acid than H2
(E) The reaction essentially goes to completion.

Questions 40:
What information about the subatomic particles in a particular carbon atom could be determined from the name carbon-13?
I. The number of protons
II. The number of neutrons
III. The number of electrons
(A) I only
(B) III only
(C) I and II only
(D) I, II, and III
(E) II and III only

Questions 41:
Which of the following salts will hydrolyze in water to form basic solutions?
I. NaCl
II. CuSO4
III. K3PO4
(A) I only
(B) III only
(C) I and II only
(D) II and III only
(E) I, II, and III

Questions 42:
When 1 mole of NaCl is dissolved in grams of water, the boiling point of the water is changed more than when 1 mole of which other substance is added to the same mass of water?
(A) CaCl2
(B) C2H5OH
(C) AlBr3
(D) MgF2
(E) FeCl3

Questions 43:
What is the structure associated with the BF3 molecule?
(A) Linear
(B) Trigonal planar
(C) Tetrahedron
(D) Trigonal pyramidal
(C) Bent or V-shaped

Questions 44 and 45:
refer to the following setup:
sat-physics-subject-test-practice-test-3-380-44

44. What letter designates an error in this laboratory setup?
(A) A (upper part of tube)
(B) B (lower part of tube)
(C) C
(D) D
(E) E

45. If the reaction in question 44 created a gas, to where would the contents of the flask be expelled under these conditions?
(A) A
(B) B
(C) C
(D) D
(E) E
___________________________

Questions 46:
The most active nonmetal has
(A) a high electronegativity
(B) a low electronegativity
(C) a medium electronegativity
(D) large atomic radii
(E) a deliquescent property

Questions 47:
In the reaction Fe + S → FeS, which is true?
(A) Fe + 2e- → Fe2+
(B) Fe → Fe2+ + 2e-
(C) Fe2+ →Fe + 2e-
(D) S → S2- + 2e-
(E) S2- + 2e- → S

Questions 48:
What is the pH of a solution with a hydroxide ion concentration of 0.00001 mole/liter?
(A) -5
(B) -1
(C) 5
(D) 9
(E) 14

Questions 49:
Hydrogen peroxide decomposes into water and oxygen according to the following equation.
2 H2O2(aq) → 2 H2O(ℓ) + O2(g)
The oxygen is being
(A) oxidized only
(B) reduced only
(C) both oxidized and reduced
(D) neither oxidized nor reduced
(E) acidified

Questions 50:
....C2H4(g) +.....O2(g) → ........CO2(g) +.......H2O(l)
If the equation for the above reaction is balanced with whole-number coefficients, what is the coefficient for oxygen gas?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Questions 51:
It is found that 273 L of a gas at 0.821 atm and a temperature of 273 K has a mass of 40.0 grams.What is the molar mass of the gas in g/mol?
(A) 22.4
(B)
28.0
(C)
14.0
(D)
4.00
(E)
2.00

Questions 52:
A compound whose molecular mass is grams contains 40.0% carbon, 6.67% hydrogen, and 53.33% oxygen. What is the true formula of the compound?
(A) C2H2O4
(B) CH2O4
(C) C3H6O
(D) C3HO3
(E) C3H6O3

Questions 53:
How many moles of CaO are needed to react with an excess of water to form 370 grams of calcium hydroxide?
(A) 1.0
(B) 2.0
(C) 3.0
(D) 4.0
(E) 5.0

Questions 54:
To what volume, in milliliters, must 50.0 milliliters of 3.50 M H2SO4 be diluted in order to make 2.00 M H2SO4?
(A) 0
(B) 1
(C) 5
(D) 2
(E) 101

Questions 55:
A small value of Keq, indicates that equilibrium occurs
(A) at a low product concentration
(B) at a high product concentration
(C) after considerable time
(D) with the help of a catalyst
(E) with no forward reaction
Questions 56:
A student measured 10.0 milliliters of an HCl solution into a beaker and titrated it with a standard NaOH solution that was 0.09 M.The initial NaOH burette reading was 34.7 milliliters while the final reading showed 49.2 milliliters.What is the molarity of the HCl solution?
(A) 0.13
(B) 0.47
(C) 0.52
(D) 1.57
(E) 2.43

Questions 57:
A student made the following observations in the laboratory:
(a) Sodium metal reacted vigorously with water while a strip of magnesium did not seem to react at all.
(b) The magnesium strip reacted with dilute hydrochloric acid faster than an iron strip.
(c) A copper rivet suspended in silver nitrate solution was covered with silver-colored stalactites in several days, and the resulting solution had a blue color.
(d) Iron filings dropped into the blue solution were coated with an orange color.
The order of decreasing strength as reducing agents is:
(A) Na, Mg, Fe, Ag, Cu
(B) Mg, Na, Fe, Cu, Ag
(C) Ag, Cu, Fe, Mg, Na
(D) Na, Fe, Mg, Cu, Ag
(E) Na, Mg, Fe, Cu, Ag

Questions 58:
A sample of ethyl alcohol and water that were previously mixed in the laboratory must now be separated. Which separation technique could accomplish this?
(A) Filtration
(B) Magnetism
(C) Visual inspection
(D) Distillation
(E) Separating funnel

Questions 59:
Which of these statements is NOT correct?
(A) In an exothermic reaction, ΔH is negative and the enthalpy decreases.
(B) In an endothermic reaction, ΔH is positive and the enthalpy increases.
(C) In a reaction where ΔG is negative, the forward reaction is spontaneous.
(D) In a reaction where ΔG is positive, AS may also be positive.
(E) In a reaction where ΔH is positive and ΔS is negative, the forward reaction is spontaneous.

Questions 60:
A student filled a eudiometer with 32. milliliters of oxygen and 4.0 milliliters of hydrogen over mercury. How much of which gas would be left uncombined after the mixture was sparked?
(A) None of either
(B) 3.0 mL H2
(C) 24 mL O2
(D) 28 mL O2
(E) 30.mL O2

Questions 61:
What would be the total volume, in milliliters, of gases in question 60 after sparking?
(A) 16
(B) 24
(C) 34
(D) 36
(E) 40

Questions 62:
How can the addition of a catalyst affect an exothermic reaction?
I. Speed up the reaction.
II. Slow down the reaction.
III. Increase the amount of product formed.
(A) I only
(B) II only
(C) I and II only
(D) II and III only
(E) I, II, and III

Questions 63:
In which period of the periodic table is the most electronegative element found?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Questions 64:
What could be the equilibrium constant for this reaction: aA + bB ⇌ cC + dD, if A and D are solids?
sat-physics-subject-test-practice-test-3-382-64

Questions 65:
Which of the following does NOT react with a dilute solution of sulfuric acid?
(A) NaNO3
(B) Na2S
(C) Na3PO4
(D) Na2CO3
(E) NaOH

Questions 66:
Which of these statements is the best explanation for the sp3 hybridization of carbon’s electrons in methane, CH4?
(A) The new orbitals are one s orbital and three p
(B) The 5 electron is promoted to the p
(C) The s orbital is deformed into a p orbital.
(D) Four new and equivalent orbitals are formed.
(E) The s orbital electron loses energy to fall back into a partially filled p orbital.

Questions 67:
The intermolecular force that is most significant in explaining the variation of the boiling point of water from the boiling points of similarly structured molecules is
(A) hydrogen bonding
(B) van der Waals forces
(C) covalent bonding
(D) ionic bonding
(E) coordinate covalent bonding

Questions 68:
If K for the reaction H2 + I2 ⇌ 2HI is equal to 45.9 at 450°C, and 1 mole of H2 and 1 mole of I2 are introduced into a 1-liter box at that temperature, what will be the expression for K at equilibrium?
sat-physics-subject-test-practice-test-3-383-68

Questions 69:
In the decomposition reaction of potassium chlorate, if 96.0 grams of oxygen are produced, the mass of potassium chloride produced would be
(A) 149.2 grams
(B) 74.2 grams
(C) 37.1 grams
(D) 96.0 grams
(E) unable to be determined

ANSWER SHEET
Practice Test 3

sat-chemistry-subject-test-practice-test-3-ANS

ANSWERS EXPLAINED

Answer 1:
(B) The activation energy of the forward reaction is the energy needed to begin the reaction.

Answer 2:
(D) For the reverse reaction to occur, activation energy equal to the sum of (B) + (C) is needed. This is shown by (D).

Answer 3:
(C) The heat of the reaction is the heat liberated between the level of potential energy of the reactants and that of the products. This is quantity (C) on the diagram.

Answer 4:
(A) The potential energy of the reactants is the total of the original potential energies of the reactants shown by (A).

Answer 5:
(B) This is a single replacement reaction in which aluminum chloride forms. The formula for aluminum chloride is AlCl3.

Answer 6:
(D) The oxidation state of aluminum is changing from 0 to +3; therefore, the aluminum is being oxidized.

Answer 7:
(E) The original solution of CuCl2 is blue due to the presence of Cu2+ ions in solution. The copper(II) ions are being used in the reaction; therefore, the concentration of the copper(II) ion will be decreasing and the solution will become less blue as time goes by.

Answer 8:
(C) This equation shows the volume decreasing as the pressure is increased when the temperature is held constant. It is an example of Boyle’s Law.

Answer 9:
(B) This equation shows the pressure increasing as the temperature is increased when the volume is held constant. It is an example of Gay-Lussac’s Law.

Answer 10:
(A) This equation shows the volume increasing as the temperature is increased when the pressure is held constant. It is an example of Charles’s Law.

Answer 11:
(D) This equation shows that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases.

Answer 12:
(B) The balanced reaction equation is:
2NaI(aq) + Pb(NO3)2(aq) → 2NaNO3(aq) + Pbl2(s)

Answer 13:
(A) The balanced reaction equation shows that 1 mole of Pbl2 is produced from 2 moles of Nal. Therefore, only 1 mole of Nal would be required to make 0.5 mole of Pbl2.

Answer 14:
(B) NaNO3 is an ionic substance that dissociates into two ions, Na+ and NO3 .

Answer 15:
(A) MgCl2 is ionic because it is the product of an active metal (Mg) combining with a very active nonmetal (Cl).

Answer 16:
(B) The electronegativity difference between H and Cl is between 0.5 and 1.7. This indicates an unequal sharing of electrons, which results in a polar covalent bond.

Answer 17:
(C) Ethane, CH3-CH3(g), has symmetrically arranged C-H polar bonds so that the ethane molecule is nonpolar covalent.

Answer 18:
(E) Cu(s) is a metal

Answer 19:
(D) When hydrated copper sulfate is heated, the crystal crumples as the water is forced out of the structure, and a white powder is the result.

Answer 20:
(A) When an ionic substance dissolves in water, the ionic substance breaks up into the ions that make it up. This process is called dissociation.

Answer 21:
(C) Phenolphthalein is used as an acid-base indicator because it turns pink in the presence of a base.

Answer 22:
(B) A substance that can act as both an acid and a base depending on what it is in the presence of is said to be amphoteric.

Answer 23:
(E) Hygroscopic materials have the ability to absorb moisture from the air. Some hygroscopic materials have such an ability to do so that they can dissolve into a puddle from that moisture. Such substances are said to be deliquescent.

Answer 101:
(T, F) The assertion is true that the most active metals are found in the upper left corner of the Periodic Table because of their ability to lose their outer electron(s). These metals actually have smaller ionic radii than their atomic radii.

Answer 102:
(T, T, CE) The assertion is explained by the reason. The graphic display of this is:
sat-chemistry-subject-test-practice-test-3-101

Answer 103:
(T, F) The assertion is true but the reasoning is false. Transition elements have incom­plete inner energy levels that are being filled with the additional electrons, thus leaving the outer energy level the same in most cases. As a result, these elements have common oxidation numbers.

Answer 104:
(F, T) The assertion is false and the reason is true. A supersaturated solution is holding more than its normal solubility, and the addition of a crystal causes crystallization to occur.

Answer 105:
(F, T) Equilibrium is a dynamic condition because of the reason stated. The assertion is false; the reason, true.

Answer 106:
(F, T) Covalent bonds are stronger than ionic bonds, generally.

Answer 107:
(T, T, CE) An equilibrium system must have a gaseous reactant or product for pressure to affect the equilibrium. Then increased pressure will cause the reaction to go in the direction that reduces the concentration of gaseous substances. Since four volumes of gases on the left became two volumes on the right, the reaction shifts to the right.

Answer 108:
(T, T, CE) The assertion is explained by the reason; both are true.

Answer 109:
(T, T, CE) Both the assertion and the reason are true; they explain that the element’s orbital designation places it in the first transition series of filling the 3d orbitals.

Answer 110:
(T, T, CE) The assertion is true; the reason is true and explains why nonmetals have the highest electronegativity.

Answer 111:
(T, T, CE) The assertion is explained by the reason; both are true.

Answer 112:
(T, T) There are 3 moles of atoms in 18 g of water because 18 g is 1 mol of water mol­ecules and each molecule has three atoms. The reason does not explain the assertion but is also true.

Answer 113:
(F, T) Benzene is a nonionizing substance and therefore a nonelectrolyte. The reason is a true statement.

Answer 114:
(T, F) Isomers have the same empirical formula but vary in their structural formulas.

Answer 115:
(T, T) The reaction does go to completion, but a gaseous product is formed, not a precipitate, so II does not explain I.

Answer 116:
(F, T) In the Rutherford experiment relatively few alpha particles were deflected, indi­cating a great deal of empty space in the atom. The reason is a true statement.

Answer 24:
(B) The correct coefficients are 2, 13, 8, and 10.

Answer 25:
(P) 1K + 1Al + 2S + 8O = 12 total

Answer 26:
(D) Air is a mixture; all others are compounds. Washing soda (C) is sodium carbonate, and lime (E) is calcium oxide.

Answer 27:
(D) One mole of a gas at STP occupies 22.4 L. So two moles of a gas at STP occupy 2.0 mol × 4 L = 44.8 L.

Answer 28:
(D) The maximum number of electrons in each kind of orbital is:
s = 2 in one orbital
p = 6 in three orbitals
d = 10 in five orbitals
f = 14 in seven orbitals

Answer 29:
(E) The element with atomic number 11 is sodium with 1 electron in the 3s orbital. It would readily combine with the element that has 3p5 as the outer orbital since it needs only 1 more electron to fill it.

Answer 30:
(D) The only physical property named in the list is low melting point.

Answer 31:
(A) If the gas is diatomic, then 6.02 × 1023 atoms will form 6.02 × 1023/2 molecules. At STP, 6.02 × 1023 molecules occupy 22.4 L, so half that number will occupy 11.2 L.

Answer 32:
(E) Cascading excited electrons can fall only to lower energy levels that are unfilled.

Answer 33:
(B) Mass spectroscopy uses a magnetic field to separate isotopes by bending their path. The lighter ones are bent farther than the heavier ones.

Answer 34:
(A) The pi bond is a bond between two p orbitals, like this:
sat-chemistry-subject-test-practice-test-3-34

Answer 35:
(C) At Pikes Peak (alt. approx. 14,000 ft) the pressure is lower than at ground level; therefore the vapor pressure at a lower temperature will equal the outside pressure and boiling will occur.

Answer 36:
(C) The alkanes contain the sp3 hybrid orbitals.

Answer 37:
(E) I, II, and III are correct.

Answer 38:
(A) Only I is correct.

Answer 39:
(D) HCl is actually a stronger Bronsted-Lowry acid than H2O, which is why the reaction occurs as shown.

Answer 40:
(D) The name carbon-13 supplies enough information to determine the number of all three subatomic particles. The name carbon indicates 6 protons as carbon has only 6 protons. Since atoms are neutral, an equal number of electrons must be present; there­fore, carbon-13 has 6 electrons. The number that follows the name, 13, indicates the mass number of the atom, which counts the number of protons and neutrons. Since the atom has 6 protons, it must contain 7 neutrons.

Answer 41:
(B) III is a salt from a strong base and a weak acid, which hydrolyzes to form a basic solution with water.

Answer 42:
(B) Since NaCl dissociates into two ions, it can change the boiling point of water more than the ethyl alcohol does, which does not dissociate. Colligative properties depend on the number of solute particles present in the solution. All the other substances dis­sociate into more particles per formula unit.

Answer 43:
(B) The VSEPR model shows BF3 is trigonal planar and so is related to the triangle shape on one plane.

Answer 44:
(C) The delivery tube is below the fluid level in the flask and will cause liquid to be forced up the thisde tube when gas is evolved in the reaction.

Answer 45:
(A) At first the fluid will be expelled up the thisde tube by the gas generated and exert­ing pressure in the reaction flask. When the level of the fluid falls below the end of the thisde tube, the gas will then be released through the thisde tube.

Answer 46:
(A) The most active nonmetal has a high attraction for another electron—thus high electronegativity.

Answer 47:
(B) Fe loses electrons to form the Fe2 ion.

Answer 48:
(D) The Kw of water = [H+][OH ] = 10-14. If [OH ] = 10-5 mol/L, then
[H+] = 10-14/10-5 =10-9
pH = -log[H+] (by definition)
pH = -[-9]
pH = 9

Answer 49:
(C) The oxidation state of oxygen in hydrogen peroxide (H2O2) is -1. In the products the oxidation state is both -2 (in H2O) and 0 (in O2). Therefore, the oxygen is being both oxidized and reduced. This process is called disproportionation.

Answer 50:
(C) The correctly balanced equation is
C2H4(g) + 3O2(g) → 2CO2(g) + 2H2O(l)

Answer 51:
(D) The values provided should be plugged into the Ideal Gas Law to solve for the number of moles of gas present.
sat-chemistry-subject-test-practice-test-3-51
To find the molar mass of the gas, the mass of the sample must be divided by the number of moles of the gas in the sample. Therefore, 40.0 g/10.0 moles gives a molar mass of 4.00 g/mol.

Answer 52:
(E) To find the simple or empirical formula, divide each % by the element’s atomic mass.
sat-chemistry-subject-test-practice-test-3-52-1
Next, divide each quotient by the smallest quotient in an attempt to get small whole numbers.
sat-chemistry-subject-test-practice-test-3-52-2
The simplest formula is CH2O, which has a molecular mass of 30. The true molecular mass is given as 90.0, which is three times the simplest. Therefore, the true formula is C3H6O3.

Answer 53:
(E) The reaction is:
sat-chemistry-subject-test-practice-test-3-53-1
370 g ÷ 74 = 5.0 mol of Ca(OH)2 is wanted. The reaction equation shows 1 mol of CaO produces 1 mol of Ca(OH)2, so the answer is 5.0 mol.

Answer 54:
(C) In dilution problems, this formula can be used:
"sat-chemistry-subject-test-practice-test-3-54
x = 87.5 mL, new volume after dilution

Answer 55:
(A) For Keq to be small, the numerator, which is made up of the concentration(s) of the product(s) at equilibrium, must be smaller than the denominator.

Answer 56:
(A) The amount of NaOH used is
sat-chemistry-subject-test-practice-test-3-56

Answer 57:
(E) The reactions recorded indicated that the ease of losing electrons is greater in sodium than magnesium, greater in magnesium than iron, greater in iron than copper, and finally greater in copper than silver.

Answer 58:
(D) Distillation takes advantage of the boiling point differences between two liquids in a mixture. Since water and ethyl alcohol have different boiling points, they could be separated via this method.

Answer 59:
(E) All the first four statements are correct.
The Gibbs free-energy equation is:
ΔG = ΔH- TΔS
In choice (E), if ΔH is positive and ΔS is negative, then ΔG will definitely be positive, which means that the forward reaction will not occur spontaneously.

Answer 60:
(E) H2 to O2 ratio by volume is 2 : 1 in the formation of water. Therefore, 4.0 mL H2 will . react with 2.0 mL of O2 to make 4.0 mL of steam.
2H2(g) + O2(g) → 2H2O(g)
This leaves 30. mL of O2 uncombined.

Answer 61:
(C) There will be 30. mL of O2 + 4.0 mL of steam = 34 mL total.

Answer 62:
(A) By definition, a catalyst can be used to speed up a reaction without itself being consumed, so I is correct.

Answer 63:
(B) The most electronegative element is fluorine (F), found in period 2.

Answer 64:
(C) Solids are incorporated into the K value and therefore do not appear in the equi­librium constant expression.

Answer 65:
(A) Only NaNO3 will not react because it is a neutral substance.

Answer 66:
(D) When hybridization forms the sp3 orbitals in methane, CH4, four entirely new orbit­als, different from but equivalent to the former s and p orbitals, result.

Answer 67:
(A) Hydrogen bonding between water molecules causes the boiling point to be higher than would be expected.

Answer 68:
(B) At the beginning of the reaction
sat-chemistry-subject-test-practice-test-3-68

Answer 69:
(A) The decomposition reaction of potassium chlorate is
2KClO3(s) → 2KCl(s) + 3O2(g)
Since 96.0 grams of O2 were produced, which is 3 moles of O2, then 2 moles of KCl were also produced. Based on the Periodic Table, 2 moles of KCl has a mass of 149.2 grams.

CALCULATING YOUR SCORE
Your score on Practice Test 3 can now be computed manually. The actual test will be scored by machine, but the same method is used to arrive at the raw score. You get one point for each correct answer. For each wrong answer, you lose one-fourth of a point. Questions that you omit or that have more than one answer are not counted. On your answer sheet mark all correct answers with a "C” and all incorrect answers with an “X.”

Determining Your Raw Test Score.
Total the number of correct answers you have recorded on your answer sheet. It should be the same as the total of all the numbers you place in the block in the lower left corner of each area of the Subject Area summary in the next section.
A. Enter the total number of correct answers here:_______
Now count the number of wrong answers you recorded on your answer sheet.
B. Enter the total number of wrong answers here:________
Multiply the number of wrong answers in B by 0.25.
C. Enter that product here:______
Subtract the result in C from the total number of right answers in A.
D. Enter the result of your subtraction here:_______
E.
Round the result in D to the nearest whole number:________ .
This is your raw test score.

Conversion of Raw Scores to Scaled Scores
Your raw score is converted by the College Board into a scaled score. The College Board scores range from 200 to 800. This conversion is done to ensure that a score earned on any edition of a particular SAT Subject Test in Chemistry is comparable to the same scaled score earned on any other edition of the same test. Because some editions of the tests may be slightly easier or more difficult than others, scaled scores are adjusted so that they indicate the same level of performance regardless of the edition of the test taken and the ability of the group that takes it. Consequently, a specific raw score on one edition of a particular test will not neces­sarily translate to the same scaled score on another edition of the same test.
Because the practice tests in this book have no large population of scores with which they can be scaled, scaled scores cannot be determined.
Results from previous SAT Chemistry tests appear to indicate that the conversion of raw scores to scaled scores GENERALLY follows this pattern:
sat-chemistry-subject-test-practice-test-3-392-1
Note that this scale provides only a general idea of what a raw score may translate into on a scaled score range of 800-200. Scaling on every test is usually slightly different. Some students who had taken the SAT Subject Test in Chemistry after using this book had reported that they have scored slightly higher on the SAT test than on the practice tests in this book. They all reported that preparing well for the test paid off in a better score!

DIAGNOSING YOUR NEEDS
After taking Practice Test 3, check your answers against the correct ones. Then fill in the chart
below.
In the space under each question number, place a check if you answered that question correctly.

EXAMPLE__________________________________________
If your answer to question 5 was correct, place a check in the appropriate box.
Next, total the check marks for each section and insert the number in the designated block. Now do the arithmetic indicated and insert your percent for each area.
sat-chemistry-subject-test-practice-test-3-393-1
sat-chemistry-subject-test-practice-test-3-394-1

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