1. There are two stable isotopes of chlorine: chlorine-35, with a mass of 34.968853 amu; and chlorine-37, with a mass of 36.965903. Given that the average atomic mass of a chlorine atom is 35.45 amu, which of the following statements is true?
A)Chlorine contains almost exclusively of Cl, with very littleCl.
B)Chlorine contains more Cl than Cl.
C)Chlorine contains roughly equal amounts of Cl and Cl.
D)Chlorine contains more Cl thanCl.
E)Chlorine contains almost exclusively of Cl, with very littleCl.
2. What is the average mass, in grams, of one potassium atom?
A)5.14 10–23 gD)31.0 g
B)6.49 10–23 gE)39.1 g
C)6.02 10–18 g
3. Which one of the following does not represent 1.00 mol of the indicated substance?
A)6.02 1023 C atomsD)65.4 g Zn
B)26.0 g FeE)6.02 1023 Fe atoms
C)12.01 g C
4. Determine the number of moles of aluminum in 96.7 g of Al.
A) 0.279 mol B) 3.58 mol C) 7.43 mol D) 4.21 mol E) 6.02 1023 mol
5. A gold wire has a diameter of 1.00 mm. What length of this wire contains exactly 1.00 mol of gold? (density of Au = 17.0 g/cm3)
A) 2630 m B) 3.69 m C) 251 m D) 14.8 m E) 62.7 m
6.How many atoms are in 4.39 g of CO2?
A)1.80 1023 atomsD)6.04 1024 atoms
B)6.01 1022 atomsE)1.81 1025 atoms
C)1.16 1026 atoms
7. Calculate the molecular mass of menthol, C10H20O.
A) 156 amu B) 140 amu C) 29 amu D) 146 amu E) 136 amu
8. Calculate the mass of 3.00 moles of CF2Cl2.
A) 3.00 g B) 174 g C) 363 g D) 1.81 1024 g E) 40.3 g
9. The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet?
A)2.77 moleculesD)1.67 1021 molecules
B)2.77 10–3 moleculesE)None of these is correct.
C)1.67 1024 molecules
10. The percent composition by mass of a compound is 76.0% C, 12.8% H, and 11.2% O. The molar mass of this compound is 284.5 g/mol. What is the molecular formula of the compound?
A) C10H6O B) C9H18O C) C16H28O4 D) C20H12O2 E) C18H36O2
11.An organic thiol compound is 38.66% C, 9.73% H, and 51.61% S by mass. What is the empirical formula of this compound?
A) C2H6S B) C3H8S C) C4H10S D) C4H12S E) C5H14S
12. Which one of the following chemical reactions is balanced?
A)HCl + KMnO4 Cl2 + MnO2 + H2O + KCl
B)HCl + KMnO4 Cl2 + MnO2 + 2H2O + KCl
C)2HCl + 2KMnO4 Cl2 + MnO2 + 2H2O + 2KCl
D)6HCl + 2KMnO4 2Cl2 + 2MnO2 + 4H2O + 2KCl
E)8HCl + 2KMnO4 3Cl2 + 2MnO2 + 4H2O + 2KCl
13.What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers?
___ Na + ___ H2O ___ NaOH + ___ H2
A) 1 B) 2 C) 3 D) 4 E) 5
14.Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor:
4NH3 + 5O2 4NO + 6H2O
When 40.0 g NH3 and 50.0 g O2 are allowed to react, which is the limiting reagent?
A) NH3 B) O2 C) NO D) H2O E) No reagent is limiting
15.What is the theoretical yield of PI3 from the reaction of 27.0 g of P and 68.0 g of I2? If only 50.2 g PI3 is obtained, what is the percent yield?
2P(s) + 3I2(s) 2PI3(s)
16. Which of the following compounds is a strong electrolyte? Section:4.1
A) H2O B) CH3OH C) CH3CH2OH D) HF E) NaF
17. Which of the following compounds is a weak electrolyte? Section:4.1
A)HClD)O2
B)CH3COOH (acetic acid)E)NaCl
C) C6H12O6 (glucose)
18. Based on the solubility rules, which one of the following compounds should be insoluble in water?
A) NaCl B) MgBr2 C) FeCl2 D) AgBr E) ZnCl2 Section:4.2
19. Which of the following is the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed?
A)Pb(NO3)2(aq) + 2NH4Cl(aq) NH4NO3(aq) + PbCl2(s)
B)Pb2+(aq) + 2Cl–(aq) PbCl2(s)
C)Pb2+(aq) + 2NO3– (aq) + 2NH(aq) + 2Cl–(aq) 2NH(aq) + 2NO3– (aq) + PbCl2(s)
D)NH4+(aq)+ NO3– (aq) 2NH4NO3(s)
E)No reaction occurs when the solutions are mixed. Section:4.2
20. What is the correct formula of the salt formed in the neutralization reaction of hydrochloric acid with calcium hydroxide?
A) CaO B) CaCl2 C) CaH2 D) CaCl E) CaClH Section:4.3
21. The oxidation number of N in NaNO3 is
A) +6. B) +5. C) +3. D) –3. E) None of the above. Section:4.4
22. In the following redox reaction
4NH3 + 3Ca(ClO)2 2N2 + 6H2O + 3CaCl2
which element is oxidized and which is reduced?
A)H is oxidized and N is reducedD)Cl is oxidized and O is reduced
B)N is oxidized and Cl is reducedE)Cl is oxidized and N is reduced
C) N is oxidized and O is reduced Section:4.4
23. Predict the products of the following single replacement reaction.
Fe(s) + CuSO4(aq)
A)Cu(s) + FeSO4(aq)D)FeCuSO4(aq)
B)Fe(s) + Cu(s) + SO4(aq)E)FeO(s) + CuSO3(aq)
C)CuS(s) + Fe2SO4(aq) Section:4.4
24. Which of the following represents a precipitation reaction?
A)2H2(g) + O2(g) 2H2O(l)
B)CaBr2(aq) + H2SO4(aq) CaSO4(s) + 2HBr(g)
C)2KNO3(s) 2KNO2(s) + O2(g)
D)2KBr(aq) + Cl2(g) 2KCl(aq) + Br2(l)
E)2Al(s) + 3H2SO4(aq) Al2(SO4)3(aq) + 3H2(g) Section:4.4
25. What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion concentration of 0.150 M?
A) 4.15 g B) 10.4 g C) 13.8 g D) 2.07 g E) 1.49 g Section:4.5
26. A sample of 0.6760 g of an unknown compound containing barium ions (Ba2+) is dissolved
in water and treated with an excess of Na2SO4. If the mass of the BaSO4 precipitate formed is
0.4105 g, what is the percent by mass of Ba in the original unknown compound?
Section 4.6
27. During a titration the following data were collected. A 10. mL portion of an unknown monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were required to neutralize the sample. What is the molarity of the acid solution? Section 4.7