Download Review Sheet for Unit 4 Test

Review Sheet for Test 4
All questions on Test 4 will be similar to homework questions you have already done. Go back over
your homework questions. If you got a few wrong – especially if you missed several of the same
type – be sure to re-work them to find where you made your mistake(s). If you can answer the
homework questions without using your book, you should do fine on the test. Topics for review:
Can you…
…convert between moles and number of representative particles? (11.1)
…convert between moles and mass of an element or compound? (11.2-11.3)
…calculate the molar mass of a compound? (11.3)
…use moles to convert between mass and number of representative particles? (11.3)
…use percent composition to determine empirical formula? (11.4)
…determine molecular formula given empirical formula & molar mass? (11.4)
…determine the formula of a hydrate from laboratory data? (11.5)
…determine mole ratios from a balanced chemical equation? (12.1)
…solve stoichiometric problems? (12.2)
…identify the limiting and excess reactants in an equation, and calculate the amount remaining
after the reaction is complete? (12.3)
…calculate the theoretical and percent yield for a chemical reaction? (12.4)
Practice Problems
1. How many carbon atoms are in 125.0 g of glucose (C6H12O6)?
2. What is the mass of one million (1.00 x 106) gold atoms?
3. 3.76 x 1022 atoms of a metal have a mass of 7.020 g. What is the metal?
4. Butanoic acid is composed of 54.53% carbon, 36.32% oxygen, and 9.15% hydrogen. What is its
empirical formula? If its molar mass is 88.106 g/mol, what is its molecular formula?
5. A hydrate of barium hydroxide yields the following experimental data:
mass of hydrate: 52.58 g
mass of anhydrous compound: 28.56 g
What is the formula of the hydrate?
6. In the reaction 2C5H10(g) + 15O2(g) 10CO2(g) + 10H2O(g), how many moles of oxygen are
needed to completely oxidize 4.2 moles of pentene (C5H10)?
7. Copper replaces silver in the reaction Cu(s) + 2AgNO3(aq) 2Ag(s) + Cu(NO3)2(aq). If you
start with 5.00 g of silver nitrate, what is the theoretical yield of silver?
If you recover 3.06 g of silver, what is your percent yield?
8. Vinegar reacts with baking soda according to the following reaction:
CH3COOH(aq) + NaHCO3(s) CH3COONa(aq) + CO2(g) + H2O(l)
If you have 168 g CH3COOH and 218 g NaHCO3, which is in excess and which is limiting?
At the end of the reaction, how much of the compound in excess will remain?
How much CO2 will be produced?