Monday, July 14, 2014

The Mole Concept Molar Mass Answers

1. What is the molar mass of MgO?

            40.3 grams/mole



2. Determine the molar mass for the following elements:

Ca                                                              Xe                                                             K
40.08 g Ca                                                131.29 g Xe                                              39.10 g K

Fe                                                              Au                                                             O
55.85 g Fe                                                 196.97 g Au                                              16.00 g O

3. Determine the molar mass for the following molecules/compounds

NaCl                                                          H2O                                                           O2
22.99 + 35.45                                            2(1.01) + 16.00                                         2(16.00)
58.44 g NaCl                                            18.02 g H2O                                             32.00 g O2

Fe2O3                                                        Na2O                                                         Cl2
2(55.85) + 3(16.00)                                  2(22.99) + 16.00                                       2(35.45)
159.70 g Fe2O3                                         61.98 g  Na2O                                          70.90 g Cl2

4. Determine the mass of the following samples

2 moles Co                                                5 moles H2                                                2.1 moles H2O
2 mol Co (58.93 g Co/1 mol Co)                                   5 mol H2 (2.02 g H2/1 mol H2)                                         2.1 mol H2O (18.02 g H2O /1 mol H2O)
117.86 g Co                                              10.10 g H2                                                 37.84 g H2O

5. Determine the number of moles in the following samples

54.2 g N2                                                   202.2 g MgO                                             519.3 g FeCl3
54.2 g N2 (1 mol N/28.02 g N2)                                                202.2 g MgO (1 mol MgO/40.31 g MgO)                               519.3 g FeCl3(1 mol N/162.20 g FeCl3)
1.93 mol N2                                              5.02 mol MgO                                         3.20 mol FeCl3

6. Determine how many atoms/molecules in the following samples

1.32 moles Si
1.32 moles Si (6.022X1023 atoms/1 mol Si)
7.95X1023 atoms Si

7.29 mol CO
7.29 mol CO(6.022X1023 molecules/1 mol CO)
4.39X1024 molecules CO

712.4 g AuCl
712.4 g AuCl (1 mol AuCl/232.42 g AuCl) (6.022X1023 molecules/1 mol AuCl)
1.85X1024 molecules AuCl



2 comments:

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    ReplyDelete
  2. sorry didn't mean to post that here

    ReplyDelete