NJSL Chemistry II Canary Exam January 10, 2019 Corrections

NJSL Chemistry II Canary Exam January 10, 2019 Corrections:

Answer the following questions on the answer sheet provided. Each correct response is worth 4 points. Use the letters in parentheses for your answers. Choose the letter that best completes or answers the item. Be certain that erasures are complete. Please PRINT your name, school area, and which test you are taking on the scantron. 1. Which element reacts fastest with water? A. S B. Cs C. Co D. Br2

2. What is the molarity of the potassium ions in 250. mL 0.133 M potassium phosphate, K3PO4?

A. 0.133 B. 0.399 C. 1.20 D. 1.60

3. A student dissolves 1.70 grams of AgNO3 in 50.0 mL distilled water. She adds this solution to 100.0 mL 0.10 M KCl solution. A second student dissolves same amount of AgNO3 in 55.0 mL of distilled water and add to 100.0 mL 0.10 M KCl solution.

Which of the following statements is correct?

A. First student will get more precipitate. B. Second student will get more precipitate. C. Both students will get the same amount of precipitate. D. Second student will get 10% more precipitate than the first student. 4. Curcumin (MW = 369 grams/mol) is one the active compounds of the turmeric and has anti-inflammatory and antibacterial properties. It is a yellow substance, insoluble in water but soluble in alcohol. A chemist extracts curcumin by dissolving 0.500 grams of turmeric in 500.0 mL of alcohol and determines the absorbance of the solution to be equal to 1.400 absorbance unit. The path length of the cuvette is 1.0 cm and the molar absorptivity of curcumin is 55, 000 L × mol-1 × cm-1. Determine the mass percent of curcumin in turmeric.

A. 0.920% B. 5.87% C. 11.7% D. 14.3%

5. Which of the following 10.0 gram-sample, when combusted, will produce highest number of moles of CO2 under the same conditions of temperature and pressure? A. C6H6 B. C6H10O C. C6H4O2 D. C6H14 6. How many grams of carbon are needed to reduce completely 16.0 grams of Fe2O3 knowing that the reaction has a percent yield of 80.0%?

2 Fe2O3 + 3 C 4 Fe + 3 CO2 A. 2.25 B. 1.50 C. 1.13 D. 0.720

NJSL Chem II Jan 10, 2019 Exam Page 1

7. The figure below represents the electron spectroscopy of _____________ and the highest intensity peak belongs to ____________ orbital electrons.

A. Sodium atom, 2p B. Aluminum ion, 3p

C. Magnesium ion, 2p D. Aluminum atom, 2p

8. Which of the following laboratory glassware would be most suitable in measuring 27.34 mL of an aqueous solution?

A. A 50-mL Erlenmeyer B. A 50-mL graduated cylinder

C. A 50-mL burette D. A 50-mL beaker

9. Which of the following atoms or ions has the largest ionic radius?

A. Se2- B. S2- C. Al3+ D. I-

10. Which of the following combinations 0.10 M of 1.0 L aqueous solutions will produce the smallest number of moles of precipitate?

A. Pb2+ and CrO42- B. Pb2+ and I- C. Ag+ and CrO4

2- D. Ca2+ and PO43-

11. How many nitrogen atoms are in 22 g N2O? A. 44 B. 6.0 × 1023 C. 3.0 × 1024 D. 3.0 × 1023

12. A compound consists of C, H, O and B. The combustion of 388 mg of this compound releases 880 mg of CO2, 270 mg of H2O and 70 mg of B2O3. What is the empirical formula of the compound? C = 12; B = 11; O = 16 and H = 1.

A. C2H3BO3 B. C5H10BO3 C. C10H10BO D. C10H15BO3


13. When the following reaction is balanced, what is the ratio of coefficients of Cu to H2O(Cu:H2O)?

Cu(s) + H+(aq) + NO3–(aq) → Cu2+(aq) + NO(g) + H2O(l)

A. 8 : 3 B. 4 : 3 C. 3 : 8 D. 3 : 4

14. Rutherford's famous experiment of scattering alpha particles with a thin metal foil led him to discover that the mass of an atom is concentrated in its nucleus. Why did Rutherford choose metallic gold in his experiment? A. Gold is very malleable element and can be rendered easily to a very thin sheets. B. Gold does not oxidize easily. C. The α-particles can easily penetrate the foil. D. All the above properties of gold were important. 15. The molecules of H2 and O2 react in the box below making water vapor, H2O. Which is the limiting react and how many water vapor molecules are produced? A. H2 and 10 molecules B. O2 and 18 molecules C. H2 and 18 molecules D. O2 and 8 molecules 16. Which of the following reactions is/are redox? I. Fe + 2 HCl FeCl2 + H2 II. 2 Fe2O3 + 3 C 4 Fe + 3 CO2 III. FeCl3 + 3 NaOH Fe(OH)3 + 3 NaCl

IV. FeCl2 + CeCl4 FeCl3 + CeCl3

A. I and III only B. III only C. I and II only D. I, II, IV only 17. Consider the following reactions: QCl2(aq) + Z(s) → Q(s) + ZCl2(aq) ZCl2(aq) + M(s) → Z(s) + MCl2(s) MCl2(aq) + Q(s) → no reaction What is the correct order of increasing activity for the metals M, Q and Z?

A. M < Q < Z B. M < Z < Q

C. Z < Q < M D. Q < Z < M


18. Which one of the following equations represents the net-ionic reaction between lead(II) nitrate and sodium sulfate aqueous solutions? A. Pb(NO3)2(aq) + Na2SO4(aq) PbSO4(s) + 2 NaNO3(aq)

B. Pb2+(aq) + SO32-(aq) PbSO3(s)

C. Pb2+(aq) + SO42-(aq) PbSO4(s)

D. Pb2+(aq) + 2 NO31-

(aq) + 2 Na1+ + SO4

2-(aq) PbSO4(s) + 2 NO31-

(aq) + 2 Na1+

19. Metallic copper does not react with dilute sulfuric acid but will react with hot concentrated sulfuric acid according the following equation: Cu(s) + 2 H2SO4(aq) CuSO4(aq) + SO2(g) + 2 H2O(l) This reaction was first discussed in an article published in the Journal of the Elisha Mitchell Scientific Society in 1895. What mass of copper can be reacted in 25.0 mL 9.00 M sulfuric acid?

A. 0.715 B. 1.17 C. 3.46 D. 7.15 20. Prussian blue is a dark blue pigment and has the chemical formula of Fe4[Fe(CN)6]3. What fraction of the total atoms are metallic? A. 4 / 43 B. 7 / 43 C. 5 /34 D. 5 / 23

21. Which scientist determined the charge to mass ratio of the electron? A. Thomson B. Millikan C. Chadwick D. Rutherford

22. Which of the following experiments can be considered as a good practical example in teaching the significant figures concept using a metric ruler and or a centigram balance? Use of the word good always creates problems. In whose opinion is the good?

I. Measuring the density of an irregular shaped object using water displacement method. (True) II. Adding water from a 10-mL graduated cylinder to a 50-mL graduated cylinder which is half-filled with water. False. III. Measuring the volume of a cubic object (using ruler to measure a side of the cube) A. Only I B. Only II C. I and III D. I, II, and III 23. What is the ground state electron configuration of the Ni+2 ion?

A. [Ar] 3d8 4s2 B. [Ar] 3d6 4s2 C. [Ar] 3d8 D. [Ar] 3d7 4s1.

24. Sulfur has four naturally occurring isotopes. Which isotope of sulfur is the most abundant?

A. Sulfur-32 B. Sulfur-33 C. Sulfur-34 D. Sulfur-36

25. Oxygen (O2) and Ozone (O3) are allotropes of the element oxygen. Which of the following pairs is NOT an allotropic pair?

A. Cgraphite and Cdiamond B. rhombic sulfur and amorphous sulfur


C. white tin and gray tin D. nitrogen-14 and nitrogen-15


Chemistry II Answer Key Canary test Corrections Date: Jan 10, 2019

1 B 6 A 11 B 16 D 21 A 2 B 7 D 12 D 17 D 22 DC 3 C 8 C 13 D 18 C 23 C 4 A 9 D 14 D 19 D 24 A 5 A 10 D 15 A 20 B 25 D

AP Chemistry Big Ideas: 1. The chemical elements are fundamental building materials of matter, and all matter can be understood in terms of arrangements of atoms. These atoms retain their identity in chemical reaction. 2. Chemical and physical properties of materials can be explained by the structure and the arrangement of atoms, ions, or molecules and the forces between them. 3. Changes in matter involve the rearrangement and /or reorganization of atoms and/or the transfer of electrons 4. Rates of chemical reactions are determined by details of the molecular collisions. 5. The laws of thermodynamics describe the essential role of energy and explain and predict the direction of changes in matter. 6. Any bond or intermolecular attraction that can be formed can be broken. There two processes are in dynamic competition, sensitive to initial conditions and external perturbations. CHEMISTRY 11 FOR ALL SECOND YEAR AND AP LEVEL STUDENTS. 25 MULTIPLE CHOICE QUESTIONS PER EXAM. JANUARY: matter and measurement, atomic theory (sub-atomic particles, atomic masses), spectroscopy (Beer’s Law), Mass Spectroscopy graphs of elements (not compounds), chemical formulas, chemical equations (precipitation reactions, ionic equations, solubility, acid-base reactions, gas forming reactions, oxidation reduction reactions, balancing redox reactions by oxidation state method, activity series, mole relationships, mass-mass problems¸ stoichiometry of redox solutions, solution stoichiometry, light, photoelectron effect, emission and absorption spectra, electronic structure and periodic table/periodicity. FEBRUARY: chemical bonding, bond order (no molecular orbital theory), doping and semiconductors, paramagnetism, and diamagnetism, electronegativity, Lewis structures, molecular geometry, polarity of molecules, hybridization(sp, sp2, sp3), intermolecular forces (van der Waals forces, relations between boiling point and vapor pressure), thermochemistry (enthalpy, Hess’s Law, heats of formation, bond energies, calorimetry), phase changes (not PT diagrams), gases and gas laws, plus January topics. MARCH: non-metals, metals (not unit cells), solutions, energetics of solution formation, kinetics, reaction mechanisms, descriptive chemistry of the elements, plus Jan and Feb topics. APRIL: chemical equilibrium, acids, bases, and salts (hydrolysis), pH, Ka, Kb, buffers, titration curves, solution equilibria, redox, voltaic cells, electrochemistry, thermodynamics (∆S, ∆H, and ∆G) , descriptive chemistry of the elements, plus Jan, Feb., and Mar topics.

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New Jersey Science League Canary Color No Corrections Chemistry II Exam February 14, 2019

Answer the following questions on the answer sheet provided. Each correct response is worth 4 points. Use the letters in parentheses for your answers. Choose the letter that best completes or answers the item. Be certain that erasures are complete. Please PRINT your name, school area, and which test you are taking on the scantron.

1. What volume of NO2Cl will be produced when 2.0 L of NO2 is mixed with 3.0 L of Cl2 in a container at 127oC and 1.5 atm? Use the balanced equation below. 2 NO2(g) + Cl2(g) 2 NO2Cl(g)

A. 2.0 L B. 3.0 L C. 3.3 L D. 4.0 L

2. According to the VSEPR theory, which of the following molecules or ions has the same shape as BH3? A. H2S B.SO2 C. NH3 D. CH3

+

3. Tutton’s salts are family of salts with the formula Q2Z(SO4)2•6H2O. These substances are double salts which contain two metal cations, Q and Z. What are the oxidation states of Q and Z in these compounds? Q Z A. +2 +1 B. +1 +2 C. +2 +2 D. +3 +1

4. Consider the following disproportionation reaction represented by the equation below: ___ CuF2 + ___ NH3 → ___Cu3N +___ NH4F + ___ N2

When this equation is balanced using the smallest-whole number coefficients, what is the coefficient of NH3? A. 16 B. 14 C. 12 D. 10 5. Identify the element in the second period (row) whose first six successive ionization energies in units of electron volts are listed below:

IE1 IE2 IE3 IE4 IE5 IE6 15 25 50 65 390 500

A. Boron B. Carbon C. Oxygen D. Fluorine 6. What is the valence electron configuration of the element Fluvarium (Z = 114)? A. 7p4 B. 7s2 7p2 C. 7s2 7p4 D. 7s2 6d10 6f14 7p4

NJSL Feb Chem II Exam 2019 Page 1

7. Which of the following atoms or ions has 2 unpaired electrons?

A. Sodium atom B. Aluminum ion

C. Carbon atom D. Calcium ion

8. Hydrogen cyanide is used in the manufacture of clear plastic such as Plexiglas. It is prepared from ammonia (NH3), O2, and natural gas (CH4).

2 NH3(g) + 3 O2(g) + 2 CH4(g) → 2 HCN(g) + 6 H2O(g)

What is the hybridization change of the carbon atoms in this reaction? A. sp2 to sp3 B. sp3 to sp2 C. sp3 to sp D. sp2 to sp 9. Which of the following gases deviates most from the ideal gas behavior at 0oC? A. NO2 B. He C. CH4 D. C2H6

10. Which of the following has the bonds arranged in order of decreasing polarity?

A. H – C > H – O > H – F B. H – O > H – N > H – C

C. H – H > H – F > H – O D. H– Se > H – S > H – O

11. Three containers are connected as shown in the a figure below. All containers are at 273 K. The two valves are turned on simultaneously. What is the pressure in the containers assuming that the temperature remained constant? Assume the tubing connecting the containers has no volume.

A. 1.0 atm B. 2.0 atm C. 3.0 atm D. 4.0 atm


12. Consider the figure given below, which represent the photoelectron spectra of two unknown elements. Which of the following can be inferred from the data?

A. Element R has higher nuclear charge than the element Q. B. Element R has a lower ionization energy than the element Q does. C. Element Q has more stable isotopes than element R D. Element Q and element R can have negative charges only.

13. Which one of the following liquids has the greatest solubility in water, H20(liq) under the same conditions of pressure and temperature?

A. CH2Cl2 B. CHCl3 C. CCl4 D. CH3CH2NH2 14. Which one of the following equations correctly represents the standard enthalpy of formation of HCN? A. H(g) + C(g) + N(g) HCN(g) B. H2(g) + C2(g) + N2(g) 2 HCN(g) C. H2(g) + 2 C(g) + N2(g) 2 HCN(g) D. ½H2(g) + C(s) + ½N2(g) HCN(g)

15. Which pairs of molecules, when dissolved in pure water, create strong electrolyte solutions?

A. C2H5OH and CH3OH B. NH4Cl and (NH4)2SO4

C. NH4OH and HF D. H3PO4 and H2O2

16. A Styrofoam cup contains 250.0 mL of 1.0 M Ba(OH)2 solution at 22oC. Next. 150.0 mL of 2.0 M of HCl solution is added to the calorimeter also at 22oC. The temperature rises by 10.0oC. If the calorimeter does not lose any heat to its surroundings, determine the heat of neutralization for this reaction? Specific heat of the final solution is 4.18 J/g×oC. The volumes are additive and the density of the final solution in the Styrofoam is 1.0 g/mL. A. +56 kJ/mol B. -56 kJ/mol C. +28 kJ/mol D. -28 kJ/mol

17. When heated, 1.20 g of MO3 react stoichiometrically with 0.648 g of Al according to the following equation:

2 MO3(s) + 4 Al(s) → 2 Al2O3(s) + 2 M(s) What is the identity of the metal? A. Mn B. Mo C. V D. Cr


18. The element Boron has two naturally occurring stable isotopes: boron-10 and boron-11. Which of the following statements is correct?

A. Boron-10 is the more abundant isotope. B. Boron-11 is the more abundant isotope. C. Both isotopes are equally abundant. D. Boron has another isotope which is not stable.

19. A hydrate contains nearly 15% of crystal water, by mass, in its solid state. What is the formula of this hydrated compound?

A. NiSO4•6H2O B. BaCl2•2H2O C. ZnSO4•7H2O D. MgSO4 •7H2O

20. Which two gases have the same diffusion rate?

A. CO and CO2 B. CH4 and C2H6 C. N2 and F2 D. CO2 and C3H8

21. Which of the following cations binds water molecules the strongest?

A. Al3+ B. Ca2+ C. K+ D. Ba2+

22. The following reaction enthalpies are given.

2 X(s) + 3Y2(g) 2 XY3(s) Ho = -1600. kJ Z(s) + Y2(g) ZY2(g) Ho = - 400. kJ 2 XZ(s) + 5 Y2(g) 2 XY3(s) + 2 ZY2(g) Ho = -2300. kJ

Using the above values, determine the enthalpy of formation of XZ(s). X(s) + Z(s) XZ(s)

A. -100. kJ/mol B. +100. kJ/mol C. -50.0 kJ/mol D. +50.0 kJ/mol

23. What is the ground state electron configuration of the nickel (III) ion? A. [Ar] 3d8 4s2 B. [Ar] 3d6 4s2 C. [Ar] 3d7 D. [Ar] 3d6 4s1

24. 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? The choices are in the order of q, W, and ΔE.

A. 250 J -460 J -210 J B. -250 J -460 J -710 J

C. 250 J 460 J 710 J D. -250 J 460 J 245 J

25. In which of the following choices are the species ordered in terms of increasing numbers of lone pairs of electrons on their central bonded atom? A. BF3 NH3 H2O B. H2O NH3 BF3 C. CH4 H2O NH3 D. CH4 H2O BH3


Chemistry II Answer Key Canary test No Corrections Date: Feb 14, 2019

1 A 6 B 11 A 16 B 21 A 2 D 7 C 12 A 17 D 22 C 3 B 8 C 13 D 18 B 23 C 4 A 9 A 14 D 19 B 24 A 5 B 10 B 15 B 20 D 25 A



Phone (cell) # 908-213-8923 fax # 908-213-9272 email: [email protected] Web address: http://entnet.com/~personal/njscil/html/

What is to be mailed back to our office? PLEASE RETURN THE AREA RECORD AND ALL TEAM MEMBER SCANTRONS

(ALL STUDENTS PLACING 1ST, 2ND, 3RD, AND 4TH). If you return Scantrons of alternates, then label them as ALTERNATES.



New Jersey Science League Canary Exam No Corrections Chemistry II Exam March 14, 2019

Answer the following questions on the answer sheet provided. Each correct response is worth 4 points. Use the letters in parentheses for your answers. Choose the letter that best completes or answers the item. Be certain that erasures are complete. Please PRINT your name, school area, and which test you are taking on the scantron.

1. Which of the following substances has a heat of formation different from the others? A. S8(s) B. Cs(s) C. HCl(g) D. Hg(l) 2. Which of these compounds has a partial covalent character? A. CO2 B. CO C. BeO D. HCl 3. The density of a gas is 0.0200 g/L at STP. What is the density of the gas at 100. K and 100. atm? A. 0.546 g/L B. 0.758 g/L C. 3.24 g/L D. 5.46 g/L 4. The mechanism of the addition reaction of C2H4 with HCl is presented by two-step elementary reactions. The overall reaction is endothermic. C2H4 + H+ C2H5

+ slow C2H5

+ + Cl- C2H5Cl fast Which of the following potential energy diagrams below outlines the above mechanism?

5. For the reaction, 2 AB(g) + C2(g) 2 A(s) + 2 BC(l), which one of the following statements is absolutely true? A. The reaction is second order with respect to AB and first order with respect to C2. B. The reaction is third order overall. C. The rate law is: rate = k [AB]2[C2]. D. The rate law cannot be determined from the information given. 6. At 300 K, the following reaction is found to obey the rate law: rate = k [NOCl]2 2 NOCl 2 NO + Cl2 Consider the three postulated mechanisms given below. Then choose the response that lists all those that are possibly correct and no others.

Mechanism 1 NOCl NO + Cl slow

Cl + NOCl NOCl2 fast

NOCl2 + NO 2NO + Cl2 fast Mechanism 2 2NOCl NOCl2 + NO slow

NOCl2 NO + Cl2 fast Mechanism 3 NOCl NO + Cl fast

NOCl + Cl NO + Cl2 slow A. Only 1 B. Only 2 C. Only 1 and 3 D. Only 2 and 3

NJSL Chem II March Exam 2019 Page 1

7. A mixture of 10.0 grams of He and 10.0 grams of Ar has a pressure of 1000. torr under conditions of constant temperature and volume. The partial pressure of He is:

A. 90.0 torr B. 400. torr C. 500. torr D. 910. torr 8. Estimate the heat of reaction at 298 K for the reaction shown, given the average bond energies below. Br2(g) + 3 F2(g) 2 BrF3(g) Br2 Bond Energy 192 kJ F2 Bond Energy 158 kJ Br-F Bond Energy 197 kJ

A. -516 kJ B. -410 kJ C. -611 kJ D. -665 kJ

9. The following reaction is performed in basic solution. What is the sum of all coefficients when the following net ionic equation is balanced using the smallest whole number coefficients possible?

ClO3- + OH- + I2 IO3

- + Cl- + H2O A. 7 B. 14 C. 21 D. 28 10. Which of the following substances is a hydride? A. HN3 B. NaOH C. NaH D. NaHCO3•10H2O 11. What is the concentration of the Cl- ions when equal volumes of equimolar (same concentration) solutions of NaCl, CaCl2, and FeCl3 are mixed together? The chloride concentration will be….. A. equal to the concentration of chloride ion in the NaCl solution. B. equal to the concentration of chloride ion in the CaCl2 solution. C. equal to the concentration of chloride ion in the FeCl3 solution. D. six times that of the NaCl solution. 12. A 25 g sample of CaCO3 was heated until 7.6 L of CO2 was collected at 427 K and 700. torr. What percentage of the CaCO3 decomposed? A. 80.% B. 17% C. 35% D. 44% 13. The salt of which of the following cations would exhibit paramagnetism to the GREATEST extent?

A. Co3+ B. Cr3+ C. Fe3+ D. Mn3+ 14. Consider the statements I and II below given about semiconductors. I. Doping Si with P creates free electrons. II. Doping Si with B creates holes. Which of the above statements is/are correct? A. Only I B. Only II C. Both I and II D. Neither I nor II 15. Which of the following bond lengths is the shortest? A. C - S B. P = P C. O = O D. C = C


16. The following choices are isoelectronic pairs. In which of these choices, does the first species have a larger atomic or ionic radius than the second one? A. O2- and F1- B. Ca2+ and Ar C. S2- and P3- D. Ba2+ and Cs1+

17. 0.29 grams of magnesium ribbon is dissolved in a calorimeter containing 40.0 mL of 1.0 M of HCl solution. The temperature of the solution raised from 22.0oC to 44.0oC. Assuming an ideal calorimeter, determine the enthalpy of the reaction. The solution has a density of 1.02 g/mL and specific heat of 4.184 J/g×oC. A. 315 kJ/mol B. -315 kJ/mol C. 501 kJ/mol D. -501 kJ/mol 18. Given the following reaction profiles for the simple A B type reaction:

Which one of the following statements is correct?

A. Reaction pathway letter A would have the slowest forward reaction rate. B. Reaction pathway letter B releases the least amount of heat energy. C. Reaction pathway letter C has the slowest reverse reaction rate. D. Reaction pathway letter D has the fastest forward rate.

19. Kinetic data are plotted below for the reaction A B at constant temperature. What is the rate constant, including the unit, for this reaction?

A. 0.120 M × s B. 0.120 M-1 × s-1 C. 0.240 M × s D. 0.240 M-1 × s


20. Which of the following interaction(s) below accurately represents a hydrogen bonding interaction?

21. Which of the following substance has the highest boiling point? A. N2 B. Cl2 C. Br2 D. CHBr3 22. A lab technician has 250.0 ml of 5.00 M solution. How many ml of water must be added to this solution to obtain a 0.250 M solution? A. 5000 B. 4750 C. 500 D. 450 23. The energy from radiation can be used to rupture chemical bonds. The bond energy of Cl-Cl is 242 kJ/mol and the green light can break the bond between two chlorine atoms. A minimum energy of 495 kJ/mol is required to break the oxygen-oxygen bond in O2. What type of electromagnetic radiation is this? Visible light range is 400 to 700 nm. A. Visible B. Infra Red C. Radio Frequency D. UV 24. Which of the following atoms has its 3d orbitals filled? A. Sulfur B. Manganese C. Bromine D. Calcium 25. A 3.90 grams sample of a liquid hydrocarbon burned in excess oxygen produces 13.2 grams CO2. What is the formula of the hydrocarbon? A. C6H12 B. C5H12 C. C7H12 D. C6H6.


Chemistry II Answer Key Canary test No Corrections Date: March 14, 2019

1 C 6 B 11 B 16 A 21 D 2 C 7 D 12 A 17 B 22 B 3 D 8 A 13 C 18 D 23 D 4 A 9 D 14 C 19 B 24 C 5 D 10 C 15 C 20 D 25 D



Phone (cell) # 908-213-8923 email: [email protected] Web address: http://entnet.com/~personal/njscil/html/

What is to be mailed back to our office? PLEASE RETURN THE AREA RECORD AND ALL TEAM MEMBER ANSWER SHEETS




New Jersey Science League Canary No Corrections Chemistry II Exam April 11, 2019

1. The following figure represents the titration of a _________ with a ___________ . A. strong acid and strong base B. weak acid and weak base C. strong base and weak acid D. weak base and strong acid

2. Which of the following choices correctly represents the strength of the acids? A. HClO < HClO2 < HClO3 < HClO4 B. HClO4 < HClO3 < HClO2 < HClO

C. HCl < H2SO3 < H2SO4 < H3PO4 D. HI < HBr < HCl < HF 3. A sample of 10.0 mL of HCl solution has a pH = 3.0. Another 10 mL of HCl sample has a pH = 5.0. These two solutions are mixed together. What is the pH of the final solution? A. 2.0 B. 3.3 C. 4.0 D. 8.0 4. Based on the data summarized in the table below, which acid is(are) strong? A. Acid # 1 B. Acid # 3 C. Acids #s 1 and 4 D. Acids #s 2 and 3 5. Consider the following system at equilibrium at 500 K. A(g) + 2 B(g) → C(s) + 2 D(g) The initial concentrations of A and B gases are 1.0 mol/L each. The equilibrium constant is equal to 4 at this temperature. Which substance has the highest concentration at equilibrium? A. A B. B C. C D. D 6. The following solutions are saturated at 25oC. Which has the highest silver ion concentration? A. Ksp of AgI = 8.0 × 10-17 B. Ksp of Ag2CO3 = 8.0 × 10-12

C. Ksp of Ag2CrO4 = 2.0 × 10-12 D. Ksp of Ag3PO4 = 2.0 × 10-18

NJSL Chem II April Exam 2019 Page 1

7. Which reaction’s rate will increase with an increase in temperature? I. CaCO3(s) CaO(s) + CO2(g) ΔH > 0 II. 2 H2(g) + O2(g) 2 H2O(g) ΔH < 0 A. Only I B. Only II C. I and II D. Neither I nor II 8. What is the mass, in grams, of one molecule of C6H6?

A. 78 B. 78 × 6.02 × 10-23 C. 6.02× 10-23 D. 78 / 6.02×1023 9. What is the net ionic equation between acetic acid, HC2H3O2, and Ca(OH)2? A. 2 HC2H3O2(aq) + Ca(OH)2(aq) Ca2+(aq) + 2 C2H3O2

-(aq) +2 H2O(l) B. 2 H+(aq) + 2 C2H3O2

-(aq) + Ca2+(aq) + 2 OH-(aq) Ca2+(aq) + 2 C2H3O2-(aq) + 2 H2O(l)

C. H+(aq) + OH-(aq) H2O(l) D. HC2H3O2(aq) + OH-(aq) C2H3O2

-(aq) + H2O(l) 10. The equilibrium constant for the reaction below is 1.2 × 10-2. What is the strongest acid in this system? HCN(aq) + C2H3O2

–(aq) → HC2H3O2(aq) + CN–(aq) A. HC2H3O2(aq) B. CN–(aq) C. HCN(aq) D. C2H3O2

–(aq) 11. The solubility product of Ag3PO4 in pure water at 298 Ksp = 2.7×10-19. What is the solubility (Molarity) of Ag3PO4 in pure water at 298 K? A. 1.0×10-5 M B. 1.0×10-10 M C. 3.3×10-5 M D. 2.5×10-7 M 12. Which would increase the partial pressure of CO2(g) at equilibrium? 2 CO(g) + O2(g) → 2 CO2(g) ΔH < 0 A. decreasing the volume of the system B. adding a noble gas to increase the pressure of the system C. removing some CO(g) from the system D. adding a catalyst 13. What is the pH of 0.0010 M NH4I aqueous solution? Kb = 1.80 × 10-5 A. 3.00 B. 6.13 C. 7.00 D. 7.87 14. Which of the following 1.0 M solutions will require the smallest volume to neutralize 50.0 mL 2.0 M NaOH solution? A. HCl B. H2CO3 C. H2SO4 D. H3PO4


15. Pure water melts at 0oC. This physical change is represented by the following equation. H2O(s) → H2O(l) What are the signs of ΔH, ΔS and ΔG, respectively, for the above process at 298 K?

A. positive, positive, positive, B. negative, negative, negative

C. positive, positive, negative D. Positive, negative, negative

16. Consider the reaction at 800 K which is at equilibrium.

2 AB(g) → A2(g) + B2(g) The equilibrium constant is 49. In an experiment 0.10 mol of AB, 0.10 mol of A2, and 0.10 mol of B2 are mixed in 10-L container. What will be the concentration of AB when the system achieves equilibrium? A. 2.0×10-3 B. 4.6×10-4 C. 6.7×10-4 D. 7.7×10-3 17. Which of the following oxides, when dissolved in water, will produce a weak basic solution? A. CaO B. MgO C. SO2 D. CO2 18. 50.00 mL of 1.0 M HCl solution is added to 50.00 mL 1.01 M of NaOH solution. What is the final pH of the solution? A. 2.301 B. 7.001 C. 11.70 D. 12.70 19. A system at equilibrium is represented by 3 A(g) + B(g) → 2 C(g) The figure to the right represents the change in concentrations of the reactants and products in time at constant temperature. What is the equilibrium constant at this temperature? A. 0.53 B. 2.2 C. 21 D. 53 20. Based on two graphs below, one can assess that A. Reaction 1 is kinetically favorable but

thermodynamically unfavorable

B. Reaction 1 is kinetically unfavorable but thermodynamically favorable C. Reaction 2 is kinetically and thermodynamically unfavorable D. Reaction 2 is kinetically and thermodynamically favorable


21. The electrolysis of a CuCl2 solution will produce A. Hydrogen gas at the cathode and oxygen gas at the anode B. Copper metal at the cathode and oxygen gas at the anode C. Copper metal at the cathode and chlorine gas at the anode D. Hydrogen gas at the cathode and chlorine gas at the anode 22. The figure below represents the equilibrium concentrations of 2 YX3(g) Y2(g) + 3 X2(g).

What is the value of the equilibrium constant? A. 0.0018 B. 5.56 C. 180 D. 556 23. A 0.50 M weak monoprotic acid has a pH = 3.0. What is the Ka of the acid? A. 1.0×10-3 B. 5.0×10-3 C. 1.0×10-6 D. 2.0×10-6 24. Which of the 0.010 M aqueous solutions has the highest pH? A. Na2SO4 B. K2S C. LiBr D. NH4Cl 25. A small volume of 6.0 M HCl solution is added to each solution below. Which one of the solutions will have the largest shift of pH? A. 10 mL 0.10 M HF + 10 mL 0.10 M NaOH B. 10 mL 0.10 M HF + 5 mL 0.10 M NaF C. 10 mL 0.10 M HF + 5 mL 0.10 M NaOH D. 10 mL 0.10 M NH3 + 10 mL 0.10 M NH4Cl


Chemistry II Answer Key Canary test No Corrections Date: April 11, 2019

1 D 6 B 11 A 16 A 21 C 2 A 7 C 12 A 17 B 22 D 3 B 8 D 13 B 18 C 23 D 4 C 9 D 14 D 19 C 24 B 5 D 10 A 15 C 20 B 25 A



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Periodic Table and Chemistry Formulae Updated 12-18-2018

CHEMISTRY FORMULAS GASES, LIQUIDS,

SOLUTIONS PV = nRT

(P + n2a) (V−nb) = nRT

V2

PA = Ptotal • XA

Ptotal = PA + PB + PC +

n = m M

Kelvin = oC + 273

P1V1 = P2V2

V1 = V2 T1 T2

P1 V1 = P2 V2

T1 T2

d = m V

urms = mkt3

= MRT3

KEper molecule = mv2

2

KE per mole = 3RT 2

2

1

rr

= 1

2

MM

M, molarity = moles solute

liter of solution

P = pressure V = volume

T = Temperature n = number of moles

d = density m = mass

v = velocity where XA = moles A

total moles urms = root-mean-square-root

KE = Kinetic energy r = rate of effusion M = Molar mass

π = osmotic pressure i = van’t Hoff factor

Kf = molal freezing point constant

Kb = molal boiling point constant

Q = reaction quotient I =current in amperes

q = charge in coulombs t = time

Eo = standard reduction potential

Keq = equilibrium constant

R, Gas constant = 8.31 Joules Mole Kelvin

= 0.0821 liter atm mole Kelvin

= 8.31 volts coulombs mole Kelvin

Boltzmann’s constant, k = 1.38 x 10−23 Joule

K Kf water = 1.86 Kelvin /molal

Kb water = 0.512 Kelvin /molal

STP = 0.00 oC, 1.00 atm (101.3 kPa = 760 mm of Hg = 760 Torr)

= 14.7 psi

1 faraday ℑ = 96,500 coulombs/ mole of electrons

°C x 9/5 + 32 = °F (°F - 32) x 5/9 = °C

ATOMIC STRUCTURE ∆E = h ν c = ν λ

λ = h

m v

p = m v

En = −2.178 x 10−18 joule n2

E = energy ν = frequency λ = wavelength p = momentum

v = velocity n = principal quantum number

c = speed of light 3.00 x 108 m/s h = Planck’s constant = 6.63 x 10−34Joule s

k = Boltzmann constant = 1.38 x 10−23 joule/K

Avogadro’s number = 6.02 x 1023 molecules/mole

e = electron charge = −1.602 x 10−19 coulomb

1 electron volt/atom = 96.5 x 1023 kj/mole

OXIDATION-REDUCTION ELECTROCHEMISTRY

Q = [C]c[D]d [A]a[B]b

where a B + b B ↔ c C + d D

I = q/t I = amperes, q = charge in coulombs, t = time in seconds.

Ecell = Eo

cell −RT lnQ = Eocell − 0.0592 log Q @ 25oC

nℑ n

log K = nEo 0.0592

1 Faraday ℑ = 96,500 coulombs/mole

EQUILIBRIUM Kw = 1 x 10−14 at 25oC

pH = −log[H+]; pOH = −log[OH−]

pH + pOH = 14

pH = pKa + log [A−1] [HA]

pOH = pKb + log [HB+]

[B] Ka x Kb = Kw at 25oC

pKa = −logKa, pKb = −logKb

Kp = Kc (RT)∆n ∆n = moles product gas − moles reactant gas

EQUILIBIRUM TERMS

Ka = weak acid Kb = weak base

Kw = water Kp = gas pressure

Kc = molar concentration

KINETICS EQUATIONS ktAAo =− A0 is initial concentration, amount.

ktAAo =ln

ktAA o

=−11

−=

211

2 11lnTTR

Ekk a

THERMOCHEMISTRY

∆So = ∑∆So products − ∑∆So reactants

∆Ho = ∑∆Ho products − ∑∆Ho reactants

∆Go = ∑∆Go products − ∑∆Go reactants

∆Go = ∆Ho − T∆So ∆Go = −RT lnK = −2.303 RT log K

∆Go = −nℑEo

∆G = ∆Go + RT lnQ = ∆Go + 2.303 RT log Q

q = m C∆T

Cp = ∆H ∆T q = mHf

q = mHv. ∆U = ∆H-P∆V

So = standard entropy Ho = standard enthalpy

Go = standard free energy Eo = standard reduction

potential T = temperature

q = heat c = specific heat capacity

Cp = molar heat capacity at

constant pressure 1 faraday ℑ = 96,500

coulombs/mole

Cwater = 4.18 joule g K

Water Hf = 330 joules gram Water Hv = 2260 joules gram ∆U = change internal energy of a system ∆H= change in energy of a system -P∆V = work of gases 1liter-atm = 101.325 J

Documents

NJSL Chemistry II Canary Exam January 10, 2019 Corrections