Unformatted text preview: Chem 103 Practice Questions Chapter 3 1. The structure of cinnamaldehyde (the main component of cinnamon flavoring) is shown below. What is the molecular formula of cinnamaldehyde? H H H C C C C H C C H C H C H O C H 2. What is the formula of the ionic compound that forms between the elements in each of the following pairs? a. Na and S b. Al and O c. Mg and Br 3. Name each of the following compounds. a. Ca(OH)2 b. K2HPO4 c. Co(NO3)3 d. P2S5 e. HClO3 4. Write the formula for each of the following compounds. a. magnesium chloride b. cupric carbonate c. ammonium perchlorate d. methane e. nitrous acid 5. Suppose that a reaction calls for 1.25 moles of ethanol, C2H6O (mw = 46.07 g/mol, d = 0.7893 g/cm3). What volume of ethanol should one measure out? 6. Azulene, a beautiful blue hydrocarbon (this is unusual, since most hydrocarbons are colorless), is 93.71% carbon. What is its empirical formula? 7. Nicotine is the active ingredient in tobacco. It is 74.04% C, 8.70% H, and 17.27% N. What is its empirical formula? 8. A new compound of xenon and fluorine was isolated by shining sunlight on a mixture containing 0.526 g of Xe and an excess of F2. If the mass of the product was 0.678 g, what is its empirical formula? 9. On heating a 1.687g sample of Epsom salt, MgSO4xH2O, to 250C, the water is driven off and 0.824 g of MgSO4 remains. How many waters of hydration are there in Epsom salt? (fw MgSO4 = 120.36, H2O = 18.02 g/mol) Answers 1. C9H8O 2. a. Na2S, b. Al2O3, c. MgBr2 3. a. calcium hydroxide b. potassium hydrogen phosphate c. cobalt(III) nitrate d. diphosphorus pentasulfide e. chloric acid 4. a. MgCl2, b. CuCO3, c. NH4ClO4, d. CH4, e. HNO2 5. 73.0 cm3 6. C5H4 7. C5H7N 8. XeF2 9. 7 ...
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- Spring '09
- Magnesium, H H C C C C H C C H C H C H O C, c. ammonium perchlorate