a. 36.9% b. 2.67% c. 50.4% d. 20.7% e. 12.7% 2. What is the atomic symbol for an element with 39 protons and 50 neutrons?

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1 Name: Lab Section: Use a scantron to complete the exam. There is only one best answer for each question. Good luck 1. If a gram sample of a Cu-Zn-Ni alloy contains 7.75 g Cu and g Ni, what is the percent composition of Zn? a. 36.9% b. 2.67% c. 50.4% d. 20.7% e. 12.7% 2. What is the atomic symbol for an element with 39 protons and 50 neutrons? a. b. c. d. e. 3. Rubidium (Rb) has two naturally occurring isotopes. The average mass of Rb is u. If 72.15% of Rb is found as Rb-85 ( u), what is the mass of the other isotope? a u b u c u d u e u 4. When strongly heated, boric acid breaks down to boric oxide and water. What mass of boric oxide is formed from the decomposition of 15.0 g B(OH)3? 2 B(OH)3(s) B2O3(s) + 3 H2O(g) a g b g c g d g e g 5. Which formula represents the compound formed by aluminum and carbonate ions? a. AlCO3 b. Al(CO3)2 c. Al(CO3)3 d. Al2(CO3)3 e. Al3(CO3)2 6. What is the correct formula for barium nitrate? a. Ba(NO3)2 b. BNO2 c. Ba(NO2)2 d. BaN e. BaNO3 Page VIII-7-1 /

2 7. What is the correct formula for cobalt(iii) oxide? a. CoO b. Co3O c. Co3O2 d. Co2O3 e. CoO3 8. Which of the following formulas is not correct? a. Al2(SO4)3 b. NaClO3 c. Ba2O3 d. Mg(NO3)2 e. KH2PO4 9. What is the molar mass of cobalt(ii) iodide hexahydrate? a g/mol b g/mol c g/mol d g/mol e g/mol 10. Ammonia is prepared by reacting nitrogen and hydrogen gases at high temperature according to the unbalanced chemical equation: N2(g) + H2(g) NH3(g) What are the respective coefficients when the equation is balanced with the smallest whole numbers? a. 1, 1, 1 b. 1, 3, 1 c. 1, 3, 2 d. 2, 1, 2 e. 2, 3, When methanol undergoes complete combustion, the products are carbon dioxide and water: CH3OH(l) + O2(g) CO2(g) + H2O(g) What are the respective coefficients when the equation is balanced with the smallest whole numbers? a. 1, 1, 1, 1 b. 1, 2, 1, 2 c. 2, 2, 2, 4 d. 2, 3, 2, 4 e. 2, 4, 6, What is the net ionic equation for the reaction of aqueous lead(ii) nitrate with aqueous sodium bromide? a. Pb(NO3)2(aq) + 2 NaBr(aq) PbBr2(aq) + 2 NaNO3(s) b. Na + (aq) + NO3-1 (aq) NaNO3(s) c. Pb 2+ (aq) + 2 Br -1 (aq) PbBr2(s) d. Pb 2+ (aq) + 2 Na + (aq) PbNa2(s) e. Pb(NO3)2(aq) + 2 NaBr(aq) PbBr2(s) + 2 NaNO3(aq) Page VIII-7-2 /

3 13. Which of the following are oxidation-reduction reactions? 1. Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s) 2. Pb(ClO4)2(aq) + 2 KI(aq) PbI2(s) + 2 NaClO4(aq) 3. CaCO3(s) CO2(g) + CaO(s) a. 1 only b. 2 only c. 1 and 2 d. 1 and 3 e. 2 and What is the oxidation number of each atom in potassium nitrate, KNO3? a. K = +1, N = -3, O = -2 b. K = +1, N = +5, O = -2 c. K = +1, N = -3, O = +2 d. K = -1, N = +3, O = -2 e. K = 0, N = 0, O = If g of impure soda ash (Na2CO3) is titrated with ml of M HCl, what is the percent purity of the soda ash? Na2CO3(aq) + 2 HCl(aq) 2 NaCl(aq) + H2O(l) + CO2(g) a % b % c % d % e % 16. If g MgCl2 is dissolved in enough water to make ml of solution, what is the molarity of the magnesium chloride solution? a M b M c M d M e M 17. How many liters of M KCl(aq) contain g of KCl? a L b L c L d L e L 18. When 27.0 g of an unknown metal at 88.4 C is placed in 115 g H2O at 21.0 C, the final temperature of the water is 23.7 C. What is the specific heat capacity of the metal? a J/g K b J/g K c J/g K d. 0.94J/g K e. 1.4 J/g K Page VIII-7-3 /

4 19. Calculate the amount of heat required to change 50.0 g ice at 20.0 C to steam at 135 C. (Heat of fusion = 333 J/g; heat of vaporization = 2260 J/g; specific heat capacities: ice = 2.09 J/g K, steam = 1.84 J/g K) a kj b kj c kj d. 135 kj e. 156 kj 20. Hydrazine, N2H4, is a liquid used as a rocket fuel. It reacts with oxygen to yield nitrogen gas and water: N2H4(l) + O2(g) N2(g) + 2 H2O(l) The reaction of 3.80 g N2H4 evolves 73.7 kj of heat. Calculate the enthalpy change per mole of hydrazine combusted. a kj/mol b kj/mol c kj/mol d kj/mol e kj/mol 21. Which of the following chemical equations corresponds to the standard molar enthalpy of formation of N2O? a. NO(g) + 1/2 N2(g) N2O(g) b. N2(g) + 1/2 O2(g) N2O(g) c. 2N(g) + O(g) N2O(g) d. N2(g) + O(g) N2O(g) e. 2 N2(g) + O2(g) 2 N2O(g) 22. Determine ΔH for the reaction: N2(g) + 3 H2(g) 2 NH3(g) given the thermochemical equations below. N2(g) + O2(g) 2 NO(g) ΔH = kj 4 NH3(g) + 5 O2(g) 4 NO(g) + 6 H2O(g) ΔH = kj 2 H2(g) + O2(g) 2 H2O(g) ΔH = kj a kj b kj c kj d kj e kj 23. An argon ion laser emits light at 488 nm. What is the frequency of this radiation? a s -1 b s -1 c s -1 d s -1 e s A microwave oven emits radiation with an energy of 3.98 x J/photon. What is the frequency of this radiation? a s -1 b s -1 c s -1 d s -1 e s What is the energy of a mole of photons of red light with a wavelength of 632 nm? a. 189 kj b. 252 kj c. 314 kj d. 515 kj e. 756 kj Page VIII-7-4 /

5 26. For a neutron (mass = kg) moving with a velocity of m/s, what is the de Broglie wavelength? a m b m c m d. 486 m e m 27. What type of orbital is designated n = 3, l = 2, ml = -1 and ms = + 1 /2? a. 3s b. 3p c. 3d d. 2f e. 2d 28. Which of the following is a possible set of quantum numbers for an electron in an atom? a. n = 1, l = 1, ml = 1 b. n = 2, l = 0, ml = -1 c. n = 0, l = 0, ml = 0 d. n = 3, l = 1, ml = -1 e. n = 4, l = 5, ml = What is the maximum number of orbitals that can be identified with the following quantum numbers: n = 3, l = 1, ml = 0? a. 0 b. 1 c. 3 d. 5 e Which of the following particles would be most paramagnetic? a. Se b. Cd c. Ar d. He e. Ca 31. Place the following atoms in order of increasing atomic radii: Se, O, S, and As. a. O < S < Se < As b. O < S < As > Se c. As < Se < S < O d. Se < As < S < O e. S < As < O < Se 32. What is the ground state electron configuration for Cr 3+? a. [Ar] b. [Ar]3d 3 4s 2 c. [Ar]3d 4 4s 1 d. [Ar]3d 3 e. [Ar]3d 7 4s 2 Page VIII-7-5 /