Pieces of iron metal appear on the magnesium. Name:

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1 Name: Introduction This lab will let you see examples of synthesis, decomposition, single replacement, and double replacement reactions. The reactions will be microscale, so very small amounts of chemicals will be used for each one. Safety Wear goggles and avoid getting the aqueous solutions on your skin. At the stations with Bunsen burners, assume that the metal or glass equipment is hot. Do not open a centrifuge until it has completely stopped moving. Pre-Lab Questions 1. Write the chemical formulas for the following on the lines provided. Include (s), (l), (g), or (aq). a. Solid aluminum metal c. Dihydrogen monosulfide gas b. Aqueous solution of calcium chloride d. Aqueous solution of iron (III) nitrate 2. Determine what type of reaction each of the following is: a. 2 Na (s) + Cl2 (g) 2 NaCl (s) b. LiBr (aq) + Ag(NO3) (aq) Li(NO3) (aq) + AgBr (s) c. MgSO3 (s) MgS (s) + SO2 (g) Procedure 1. Find an empty station and bring this handout to it. You can do the reactions in any order. 2. Follow the instructions in the box for that reaction, including any cleanup instructions. 3. Be sure everyone in your group observes the reactants and products. Repeat the reaction if necessary. 4. Write a chemical equation for the reaction that you saw in the space provided (change the boldfaced words into chemical symbols/formulas). Be sure that each chemical formula has either (s), (l), (g), or (aq) next to it. Leave room for coefficients to balance the equation. 5. Balance the chemical equation by placing coefficients in front of each chemical formula. 6. Determine what type of reaction you saw (synthesis, decomposition, single replacement, or double replacement) and write it in the space provided. 7. Answer the question in the space on the right. Repeat for all 9 reactions. Example: Reaction X: Add a piece of magnesium metal to the solution of iron (III) chloride. magnesium metal reacts aqueous iron (III) chloride to produce solid iron and a magnesium chloride solution Equation X: 3 Mg (s) + 2 FeCl 3 (aq) 2 Fe (s) + 3 MgCl 2 (aq) Single replacement too place? Pieces of iron metal appear on the magnesium

2 Reaction 1: Light the Bunsen burner and adjust it to get an appropriate flame. Use the tweezers to hold a piece of magnesium in the hottest part of the flame until it starts to react. Remove it from the flame as it burns. Do not look directly at the burning magnesium. magnesium metal reacts with oxygen in the air to produce solid magnesium oxide Equation 1: Reaction 2: Fill the beaker with a small amount of tap water. Use tweezers to place one piece of calcium metal in the water. Do not touch the beaker as the reaction happens. When the reaction is complete, pour the solution down the drain and rinse out the beaker with tap water. calcium metal reacts with water to produce hydrogen gas and an aqueous solution of calcium hydroxide Equation 2: Reaction 3: Light a Bunsen burner and adjust it to get a small flame. Place a small scoop of calcium carbonate in the aluminum pan (be careful, the pan may be hot). Weigh the pan with the calcium carbonate and record the mass. Place the pan on the wire gauze for 3 minutes. Use crucible tongs to handle the hot pan! When the reaction is complete, weigh the pan again and compare your two masses. Use the rubber tip of a stirring rod to wipe the solid into the waste beaker. Leave the clean pan on the counter to cool. solid calcium carbonate yields solid calcium oxide and carbon dioxide gas Equation 3:

3 Reaction 4: Use the disposable pipettes to mix a small amount (1 squirt) of each solution in a test tube. Place the test tube in the centrifuge opposite the test tube of water already there. Turn on the centrifuge by turning the knob clockwise and let it run for about 20 seconds. Turn it off by reversing the knob, wait until the spinning stops, and remove your test tube to observe the products. Pour the solution down the drain and use tap water and the test tube brush to clean out the test tube. aqueous solutions of barium nitrate and sodium sulfate react to produce a precipitate of barium sulfate and aqueous sodium nitrate. Equation 4: Reaction 5: Use the disposable pipettes to mix a small amount (1 squirt) of each solution in a test tube. Place the test tube in the centrifuge opposite the test tube of water already there. Turn on the centrifuge by turning the knob clockwise and let it run for about 20 seconds. Turn it off by reversing the knob, wait until the spinning stops, and remove your test tube to observe the products. Pour the solution down the drain and use tap water and the test tube brush to clean out the test tube. What color is the precipitate? solutions of iron (III) chloride and potassium hydroxide react to produce a precipitate of iron (III) hydroxide and aqueous potassium chloride Equation 5: Reaction 6: Place a tiny amount of zinc (1 small scoop) in the test tube. Use the pipette to add a small amount (1 squirt) of hydrochloric acid to the test tube, and close it with the stopper. Shake the test tube gently and look carefully at the metal for evidence of reaction. Pour the acid and zinc down the drain and rinse out the test tube. zinc reacts with hydrochloric acid solution to yield aqueous zinc chloride and hydrogen gas Equation 6:

4 Reaction 7: Add 1 squirt of silver nitrate to a well in the well plate (Caution: silver nitrate is harmful to skin). Place a piece of copper wire into the well with the solution and leave it there for 1 minute. Remove the wire from the well and place it on the plastic dish. Observe the wire under the microscope. When finished, place the wire in the waste beaker. Rinse the well plate with tap water and wipe up any mess around the microscope. What color is copper (II) nitrate solution? Solid copper reacts with aqueous silver nitrate to produce solid silver metal and aqueous copper (II) nitrate Equation 7: Reaction 8: Light the bunsen burner and add a tiny piece of ammonium nitrate to the evaporating dish (see the example of a tiny piece provided). Use crucible tongs to hold the evaporating dish in the flame until the reaction is complete. Observe the changes one of the products is a gas and one of the products is a liquid that boils into a gas very quickly. When finished, rest the dish on the counter and turn off the gas to the burner. Explain why nothing is left in the pan. ammonium nitrate is heated, producing dinitrogen monoxide gas and water vapor Equation 8: Reaction 9: Add 1 squirt of copper (II) chloride solution to a well in the well plate. Place a piece of aluminum foil into the well and observe the reaction. You may need to poke the foil with the stirring rod. This is a very exothermic reaction, so the bubbles are actually steam. Notice the solid on the bottom of the well. Rinse the well plate. What is the reddish-brown solid that was produced? Solid aluminum reacts with aqueous copper (II) chloride to produce copper metal and aqueous aluminum chloride solution Equation 9:

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