Unit 5 Classwork
1. NutraSweet is 57.14% C, 6.16% H, 9.52% N, and 27.18% O. Calculate the empirical
formula of NutraSweet and find the molecular formula. (The molar mass of NutraSweet
is 294.30 g/mol)
2. Natural gas is a mixture of several hydrocarbons, but is primarily methane. Find the
empirical formula of this important natural resource if its composed of 74.8% carbon and
25.2% hydrogen.
3. Upon decomposing an opal, a chemist found it to contain 4.58 g silicon and 5.21 g oxygen, plus
water and minute traces of several metals. Find the empirical formula of the basic component of
opals, and give its chemical name.
4. While trace impurities of iron and chromium in natural corundum form the gemstones
ruby and sapphire, they are basically a binary compound of aluminum and oxygen, with
52.9% Al. Find the empirical formula and give the chemical name for corundum.
5. Butyric acid gets its name from the Latin "butyrum", meaning butter, and is the compound in
rancid butter that gives it its terrible smell. A 2.50 g sample of butyric acid was found to consist
of 1.36 g carbon, 0.23 g hydrogen, and 0.91 g oxygen. Find its empirical formula.
6. An even less popular chemical among organic chemistry students than butyric acid
(because it smells much, much worse) is pyridine. Find its empirical formula if a 10.00 g
sample contains 7.59 g carbon, 0.64 g hydrogen, and the rest nitrogen.
For the following, write the reaction, balance, and classify the type of reaction
(synthesis, double replacement, combustion, single replacement, decomposition)
7.
Iron + oxygen yields iron III oxide
8. Sodium + water yields sodium hydroxide and hydrogen
9. Iron III oxide + aluminum yields iron + aluminum oxide
10. Lead II nitrate + potassium iodide yields lead II iodide + potassium nitrate
11. Glucose (C6H12O6) + oxygen yields carbon dioxide + water
12. Methane (CH4) + oxygen yields carbon dioxide + water
13. sulfur trioxide and water combine to make sulfuric acid.
14. lead II nitrate and sodium iodide react to make lead iodide and sodium nitrate.
15. calcium fluoride and sulfuric acid make calcium sulfate and hydrogen fluoride
(Hydrofluoric acid)
16. calcium carbonate will come apart when you heat it to leave calcium oxide and
carbon dioxide.
17. ammonia gas when it is pressed into water will make ammonium hydroxide.
18. sodium hydroxide neutralizes carbonic acid
19. zinc sulfide and oxygen become zinc oxide and sulfur.
20. lithium oxide and water make lithium hydroxide
21. aluminum hydroxide and sulfuric acid neutralize to make water and aluminum
sulfate.
22. sulfur burns in oxygen to make sulfur dioxide.
23. barium hydroxide and sulfuric acid make water and barium sulfate.
24. aluminum sulfate and calcium hydroxide become aluminum hydroxide and
calcium sulfate.
25. copper metal and silver nitrate react to form silver metal and copper II nitrate.
26. sodium metal and chlorine react to make sodium chloride.
27. calcium phosphate and sulfuric acid make calcium sulfate and phosphoric acid.
28. phosphoric acid plus sodium hydroxide.
29. propane burns (with oxygen)
30. zinc and copper II sulfate yield zinc sulfate and copper metal
31. sulfuric acid reacts with zinc
32. acetic acid ionizes.
33. steam methane to get hydrogen and carbon dioxide
34. calcium oxide and aluminum make aluminum oxide and calcium
35. chlorine gas and sodium bromide yield sodium chloride and bromine