Classifying Chemical Reactions

Transcription

1 Classifying Chemical Reactions Name: Partner: Discussion Question #1 will be evaluated 25 marks (5 marks per reaction) - 2 marks for correct reactants and products - 1 mark for states - 1 mark for balancing - 1 mark for type of reaction Prelab Prelab questions MUST be completed and shown to Ms. Pokoradi BEFORE beginning the lab. 1. Name the type of reaction a) NaBr + Ca(OH) 2 CaBr 2 + NaOH Type of reaction: b) NH 3 + H 2 SO 4 (NH 4 ) 2 SO 4 Type of reaction: c) Pb + H 3 PO 4 H 2 + Pb 3 (PO 4 ) 2 Type of reaction: d) HgO Hg + O 2 Type of reaction: Classifying Chemical Reactions Purpose The purpose of this lab is to perform and classify different chemical reactions, to identify the reactants and products of each reaction, and to write and balance equations for each reaction. Materials Materials and instructions will be provided for you at each station. You MUST wear goggles at all times. Procedure 1. This lab is divided into stations. Follow the instructions at each station carefully. 2. The reactants are written on the station cards. Record the reactants for each reaction in Table Record all observations for each reaction in Table 1. Include any physical observations (colour, clarity and state) and observations that suggest a chemical reaction has occurred (gas formation, temperature change, colour change).

2 Table 1: Observing Various Chemical Reactions Station Reactants Observations A B C D E

3 Discussion Questions 1. For each reaction, write the balanced chemical equation including the states, and name the type of reaction that occurred. Station Balanced Chemical Equation Type of Reaction A B C D E 2. How can you tell if a chemical reaction has occurred? What did you look for? 3. What gas was formed in Reaction A?

4 4. What gas was formed in Reaction B? 5. For Reaction C: a) If you were allowed to touch the products of the reaction, what do you think it would feel like? b) Name a different compound you could add to copper (II) sulfate to form a precipitate. Use your Solubility Table to aid in this answer. 6. Reaction D could also be used with copper wire. There is more than one possible product for the reaction of solid copper with oxygen gas. a) Name the two possible products. b) Explain a reaction that could be performed to determine which product was formed in the reaction. 7. What type of reaction would occur if the reactants used for this station were MgSO 4(aq) and Cu (s)?

5 STATION B calcium metal **Be extremely careful. This metal is reactive! water 2. Fill a beaker half full with water. 3. Using the tweezers or a scoopula add a small piece of calcium metal to the water in the beaker 4. Describe the reaction that is occurring in your table. 5. Dispose of the calcium and liquid into the waste beaker. 6. Wash the beaker. STATION A 3 mol/l hydrochloric acid (HCl) This acid will burn your skin. Wash your hands immediately if you spill any. zinc metal dust 2. Place about 2 cm of hydrochloric acid into the test tube. 3. Use a scoopula to add a small amount of zinc to the test tube. 4. Record your observations. 5. Pour the product into the waste beaker. 6. Wash the test tube.

6 STATION C 1 mol/l sodium hydroxide copper (II) sulfate 2. Place about 2 cm of sodium hydroxide into the test tube. 3. Add a few drops of copper (II) sulfate to the test tube. 4. Record your observations. You may need to make a few observations as the reaction progresses. 5. Pour the products into the waste beaker. 6. Wash the test tube. magnesium ribbon copper (II) sulfate STATION E 2. Place about 2 cm of copper (II) sulfate into the test tube. 3. Add a small piece of magnesium ribbon to the test tube. 4. Lightly swirl the test tube so that the magnesium doesn t simply sit on the top of the solution. 5. Record your observations. 6. Pour the products into the waste beaker. 7. Wash the test tube.

7 STATION D Reactant: Magnesium metal + oxygen 2. Light the Bunsen burner. 3. Using a pair of tongs, hold the magnesium ribbon over the flame. 4. Do not look directly at the magnesium in the flame. 5. Record your observations. 6. Dispose of the product in the garbage.