Title: Investigating Properties of Ionic and Covalent ...

1 Chemistry--Unit11: Ionic Bonding and Ionic Compounds Ionics and Covalents Lab title : Investigating Properties of Ionic and Covalent Compounds Date: Partners: None, Data from class will be compiled Objectives: 1. To be able to classify a compound as Ionic , Covalent , polar Covalent , or acidic based on Properties observed in a laboratory investigation. 2. To be able to offer explanations for the Properties observed. Procedure: (refer to the data table) 1. Wear goggles. 2. You will be assigned one substance to work with throughout this investigation (except for step #9). Be sure to observe what others are doing so you have the opportunity to experience the results received for other substance types. Feel free to compile data from others as you observe, as this will have to be done anyway. 3. Determine or look up the name or formula for your particular substance. Record this in the data table in Column A or B.

2 4. For Column C, the solubility of the substance in distilled water will be tested. To do this, use the scale to weight out g of your substance directly into a 50- or 100-mL beaker. Add 20 mL of distilled water and stir with a stirring rod. Note in the table whether the substance is soluble or insoluble. 5. For Column D, use your sample with water prepared above. Obtain a conductivity tester. Be sure the tester is rinsed with distilled water and dried before and after use. *Note--Do not get water on any part of the tester other than the two lead wires. This may give inaccurate results. Dip the tester wires into your beaker containing distilled water and your compound. Use the key on the back of the tester to find your conductivity level. Record this in the data table. 6. For Column E, record the natural phase your substance exists in. Some of you will be able to note this directly, while others may have to look this up.

3 7. A melting point determination will be done for Column F. If your sample is a solid, obtain a melting point tube, a rubber band, and a temperature probe. Place a small amount of your sample at the closed end of the tube and rubber-band it to end of the temperature probe. Hold the temperature probe in heating water so that the sample is submerged but does not get wet. Observe and record in the data table the temperature at which the substance melts. If the water boils and the substance does not melt, record the melting point as over 100 C. If your sample is a liquid, place a small amount of the liquid in a small test tube. Place the test tube in a salt/ice/water bath to freeze the sample. Be sure to stir the bath and add plenty of salt. Insert a temperature probe in the test tube with the sample. Observe and record in the data table the temperature at which the substance freezes.

4 If the temperature reaches 10C and the sample has not frozen, record the melting point as below 10C. 8. For Column G, look up the accepted melting point for your substance. 9. Clean up your lab station and return all materials to where you found them. Melting point tubes may be discarded. Please put all undissolved solids in the garbage can, NOT down the sink. Chemistry--Unit11: Ionic Bonding and Ionic Compounds Ionics and Covalents Lab Data Summary: A. B. C. D. E. F. G. H. Substance # Substance Formula Substance Name Solubility in Distilled Water Conductivity Phase of Matter Data Melting Point Reference Melting Point Type of Compound 1 Al(NO3)3 2 NH4Cl 3 CH3 COCH3 4 C2H5OH 5 C3H5(OH)3 6 HCl 7 NaBr 8 CH3OH 9 NaCl 10 H2SO4 11 H2O (distilled) 12 H2O (tap) Chemistry--Unit11: Ionic Bonding and Ionic Compounds Ionics and Covalents Lab A.

5 B. C. D. E. F. G. H. Substance # Substance Formula Substance Name Solubility in Distilled. Water Conductivity Phase of Matter Data Melting Point Reference Melting Point Type of Compound 13 KCl 14 lactose 15 salicylic acid 16 paraffin 17 urea 18 table sugar (sucrose) 19 MgSO4 7H2O 20 sodium bicarbonate 21 acetic acid (vinegar) 22 citric acid 23 24 Chemistry--Unit11: Ionic Bonding and Ionic Compounds Ionics and Covalents Lab Results: 1. List the Properties determined in this lab to be characteristic of Ionic compounds. 2. Explain why Ionic compounds exhibit the Properties they do. 3. List the Properties determined in this lab to be characteristic of Covalent compounds. 4. Explain why Covalent compounds exhibit the Properties they do. 5. List the Properties determined in this lab to be characteristic of polar Covalent compounds.

6 6. Explain why polar Covalent compounds exhibit the Properties they do. 7. List the Properties determined in this lab to be characteristic of acidic compounds. 8. Explain why acidic compounds exhibit the Properties they do. 9. In the data table, fill in Column H with the term Ionic , Covalent , polar Covalent , or acidic based on your collected or compiled data and your answers to # s 1-8. 10. All compounds used had different melting points. Explain why this is so. Conclusion: (see laboratory report guide sheet) Discussion of Error: (This is an observational lab, so no percent error calculation or accuracy or precision discussion is required. Instead, discuss anything that hindered you from making correct conclusions from the data gathered). Suggestions For Improvement: (Be sure to offer a reasonable suggestion to improve data collection or interpretation).