Chapter 7 Review(Part II) CP Chemistry Mrs. Klingaman
Q:1 What types of atoms are covalent (aka: molecular) compounds made of?
Q:2 True or False: When naming ionic compounds, roman numerals are used to express the charge of the transition metal ion.
Q:3 What is the prefix used for the number 7?
Q:4 What is the name of the compound CuS?
A:4 copper (II) sulfide
Q:5 What is the chemical formula for aluminum oxalate?
Q:6 What is the name of compound N2H4?
A:6 dinitrogen tetrahydride
Q:7 What are the units for molar mass?
Q:8 What is the molar mass of lithium phosphate?
A:8 Li3PO4 MM = 115.8 g/mol
Q:9 What is the % by mass of calcium in Ca(NO3)2?
A:9 MM = 164.1 g/mol (40.1/164.1) x 100 = 24.44 % Ca
Q:10 Which of the following is not a diatomic molecule: O2, N2, K2, or Br2?
A:10 K2 Br-I-N-Cl-H-O-F
Q:11 What is Avogadro’s number ? (including proper units)
A:11 6.022 x 1023 atoms or molecules /1 mole
Q:12 How many mols are there in 1.95 x 1025 molecules of CO2?
A:12 1.95 x 1025molec. CO2 1 mol CO2 6.022 x 1023molec. CO2 = 32.38 mols CO2
Q:13 What is the mass, in grams, of 0.78 mols of barium carbonate?
A:13 BaCO3 0.78 mols BaCO3 197.3 g BaCO3 1 mol BaCO3 = 153.9 g BaCO3
Q:14 A sample of sodium hydroxide has a mass of 15.2 grams. How many molecules of sodium hydroxide does it contain?
A:14 NaOH 15.2 g NaOH 1 molNaOH 6.022 x 1023molec. NaOH 40 g NaOH 1 molNaOH = 2.29 x 1023molec. NaOH
Q:15 Which of the following would be considered an empirical formula? P3O9 , N4H7, or C2H4O2 ?
Q:16 The stimulant nicotine is found to be 74.03% carbon, 17.27% nitrogen, and 8.70% hydrogen. What is its empirical formula?
Q:17 What is the % by mass of oxygen in tin (IV) oxide?
A:17 SnO2 MM = 150.7 g/mol (32/150.7) x 100 = 21.23 % O
Q:18 What is the mass, in grams, of 2.11 mols of phosphorpustrichloride?
A:18 PCl3 2.11 mols PCl3 137.5 g PCl3 1 mol PCl3 = 290.1 g PCl3