TEST 2 REVIEW

  1. Complete the missing information in the table below:
Atomic
Symbol
Number of
Protons
Number of
Neutrons
Number of
Electrons
48 64
82
  1. Diagrams below represent various nuclei. For each nucleus A-E, write the atomic symbol and indicate which are isotopes:
    Proton
    Neutron
    A

    B

    C

    D

    E
  2. What is the empirical formula for an oxide of bromine that contains bromine?
  3. Calculate the percent composition (by mass) of the elements in .
  4. Calculate the following quantities:
    a) Number of molecules in 23.5 moles of oxygen.
    b) Number of moles in molecules of .
    c) Number of molecules in 12.5 grams of .
    d) Number of grams in molecules of .
    e) Number of carbon atoms in 0.655 moles of .
    f) Grams of sodium in 85.6 g of .
  5. A sample of a gaseous compound was found to contain 2.560 g of carbon and 0.440 g of hydrogen.
    a) What is the empirical formula for this compound?
    b) If the molar mass of the compound was found to be , what is the molecular formula for this compound?
  6. An iron ore sample contains hematite and magnetite . What mass of iron (in grams) does 1.00 kg sample of this ore contain?
  7. A sample of 0.600 mole of a metal M reacts completely with excess fluorine to form 46.8 g of .
    a) How many grams of M are present in this sample of ?
    (Hint: How many moles of fluorine are present in this compound?)
    b) What element is represented by the symbol M?
  8. Name the following compounds:
    a)
    b)
    c)
    d)
    e)
    f)
  9. Write formula for each of the following compounds:
    a) calcium sulfate
    b) nickel (II) chloride
    c) ammonium chlorate
    d) phosphorus triiodide
    e) hydrosulfuric acid
    f) sodium nitride

Answers:

  1. No answers provided
B and D are isotopes; C and E are isotopes
3.
4. Cd; As; O
5. a) molecules
b) 56.8 mol
c) molecules
d) 4.40 g
e) atoms
f) 27.7 g
6 a)
b)
7. 708 g Fe
8. a) 22.8 g F
b) calcium
9. No answers provided
10. No answers provided