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 Start with Part F  Acid may not be strong enough to finish the reaction during the allowed period.

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Presentation on theme: " Start with Part F  Acid may not be strong enough to finish the reaction during the allowed period."— Presentation transcript:

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2  Start with Part F  Acid may not be strong enough to finish the reaction during the allowed period

3  Place small portion of CuSO 4 * 5H 2 O crystals in dry test tube  Use test tube holder to heat with bunsen burner  Note color change and observe the inside surface at the top of the test tube

4  Add NaHCO 3 (baking soda) into 250mL erlenmeyer flask – covering the bottom of the flask  Support flask on ring stand with wire gauze  Hold a flaming splint in the mouth of the flask, record how long it burns  Heat the flask strongly with burner until moisture is observed  Hold a flaming splint in the mouth of the flask  Record how long it burns

5  Put 20 drops of AgNO 3 sol’n in a test tube  Add small piece of copper wire  Allow few minutes for the reaction  Record your observation

6  Put 20 drops of HCl sol’n in a test tube  Add small piece of magnesium wire  Record your observation

7  Put 20 drops of DI water in a test tube  Add small piece of calcium metal  Record your observation

8  Put 10 drops of AgNO 3, Cu(NO 3 ) 2, and Al(NO 3 ) 3 sol’ns into separate test tubes (#1-3)  Add few drops of K 2 CO 3 sol’n to all 3 test tubes  Observe reactions  Record observations

9  Put 10 drops of AgNO 3, Cu(NO 3 ) 2, and Al(NO 3 ) 3 sol’ns into separate test tubes (#4-6)  Add few drops of Na 3 PO 4 sol’n to all 3 test tubes  Observe reactions  Record observations

10  Phenolphthalein is an acid-base indicator that is colorless in acidic and neutral sol’ns and pink in basic sol’ns  When you are adding base, make sure to make the pink as faint as possible!!  You have added enough base if the sol’n stays faint pink for 30 seconds

11  Put 10 drops of HNO 3 (aq), H 2 SO 4 (aq), and H 3 PO 4 (aq) into separate test tubes (#1-3)  Add one drop of phenolphthalein to each test tube  Add drops of dilute NaOH sol’n into test tube #1 until permanent color change is observed  Repeat for test tubes 2 and 3  Record the number of drops of base it takes to neutralize each acid

12  Note  HNO 3 (aq) monoprotic – releases 1 H +  H 2 SO 4 (aq) diprotic – releases 2 H +  H 3 PO 4 (aq) triprotic – releases 3 H +  Therefore, it should take twice as much base to neutralize sulfuric acid than it does nitric acid  It should also take three times as much base to neutralize phosphoric acid as it does nitric acid  **Only if they are the same concentration**

13  Obtain a post-1982 penny  Record the mint date  Use metal shears to cut the coin (figure 1) to ensure rapid/complete rxn with sulfuric acid  Accurately weigh the penny on the balance, record its mass  Drop penny into 100mL beaker  Add ~20mL of dilute sulfuric acid

14  The rxn requires ~3 hrs for the Zn in the coin to completely react  If the acid contacts your skin, wash immediately with water  When the coin stops producing gas bubbles, discard the sulfuric acid into the sink  Was coin with DI water, discard the wash sol’n  Rinse the coin with acetone, and discard sol’n  When the coin appears dry, weigh the copper shell, record the mass  Calculate the percentages of copper and zinc

15  The rxn will most likely not be complete before you leave lab. Therefore, you can come in around 4 on Wednesday to weigh your penny and finish the simple calculations for the lab.  The lab and post lab questions will be due at the beginning of next lab period.

16  Make sure that you balance the rxn’s when you are writing the products  Makes sure to write the phases

17  Use the reactions you just determined to answer #1  For #2 use the activity series from your book  For #3 use the solubility rules from your book  For #4 make sure to balance and write the phases for each reaction  #5 is not optional


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