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Lab Practice:
Solutions Containing Ions. | | Chemistry 9ºInstituto San RobertoSchool Year 2012-2013 |
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OverviewWhen sodium chloride melts, the sodium and chloride ions arefree to move throughout the molten salt. If a voltage is applied, positive ions move to the negative electrode (cathode), and negative ions move to the positive electrode (anode).ObjectivesTo show thations in solution conduct an electric current.Procedure 1. Tape the batteries together so the positive end of one touches the negative end of another. Tape the bare end of one wire to the positiveterminal of the battery assembly and the bare end of the other wore to the negative terminal.
CAUTION: Bare wire ends can be sharp and scratch skin. Handle with care. 2. Half fill the beaker withdistilled water. Hold the bare ends of the wires close together in the water. Look for the production of bubbles. They are a sign that the solution conducts electric current. 3. Repeat step 2 with tapwater, vinegar, and concentrated solutions of sucrose, sodium chloride, and baking soda (sodium hydrogen carbonate).Analyze and Conclude * Which solutions produced bubbles of gas? Explain. *Which samples did not produce bubbles of gas? Explain. * What gases from the bubbles you observe? * What is the source of these gases? * What type of ions do the solutions contain? * Would youexpect the same results if you used only one battery? If you used six batteries? Explain your answer. * What causes iron to rust? What ions are responsible for the rusting? What compound isformed?Results and FiguresYou can take pictures and include them in your Lab Report. Make sure to write all your observations and explain them in this section. | | Materials * 3-D cell batteries * Maskingtape * Two 30 cm lengths of bell wire with ends scraped bare * Beaker * Distilled water * Tap water * Vinegar * Sucrose * Sodium chloride * Baking sodaOther ResourcesChemistry...