Lab 7 Chemicals in everyday life Concepts –Positive test A test that deteemines a type of reaction based on a positive result. –Can not detrmine based on a negative result

Part A 1. NH 3 + H 2 O NH 4 + OH - Positive tests for NH 3 Warning! Ammonia is caustic Ammonia salts synthesises to ammonium in water

Part A 1. Read procedures for part A on page 68 and fill out 1 –6 pg 73 Positive tests for NH 3 Warning! Ammonia is caustic Ammonium salts decompose to ammonia when there is a strong base 1. NH 3 + H 2 O NH 4 + OH -

Part A Determine if fertilizers and smelling salts have ammonium in it by doing positive tests for ammonia

Part B Warning H 2 SO 4 and HCl causes severe burns

Part B 1. CO H + CO 2 + H 2 O Positive tests for baking soda (NaHCO 3 ) austic Carbonates react with acids to produce carbon dioxide

Part B Add a small amount of baking soda to a dry test tube Using a beral pipette add 1 or 2 drops of 18 M sulfuric acid Note the color and odor of the escaping gas Record observation and answer questions 7 Repeat procedure but use vinegar or acetic acid Record observation and answer questions 8 –Warning fan the gas do not smell it!! –Warning H 2 SO 4 causes severe burns Do a positive tests for CO 2 in baking soda

Part B 1.CO 2 + BaOH BaCO 3 (s) + H 2 O Determine if chalk contains carbon dioxide by doing Positive tests for carbon dioxide carbon dioxide and barium Hydroxide produces a white precipitate

Part B Add a small amount of chalk to a dry test tube Using a beral pipette add 1 or 2 drops of 2 M HCL Note the color and odor of the escaping gas Omit Barium Hydroxide Record observation and answer question 9 –Warning fan the gas do not smell it!! –Warning HCL causes severe burns Determine if chalk contains carbon dioxide by doing Positive tests for carbon dioxide

Part C 1.2Cl - + H 2 SO 4 2HCl (g) + SO Cl - + AgNO 3 NO 3 + AgCl (s) 1.All Cl - salts react with sulfuric acid (H 2 SO 4 ) to produce HCl (g) 2.All Cl - salts react with silver nitrate (AgNO 3 ) to produce a white precipitate AgCl (s)

Part C Add a small amount of salt to a dry test tube Using a beral pipette add 1 or 2 drops of sulfuric acid Note the color and odor of the escaping gas Record observation and answer questions 10 and 11 –Warning fan the gas do not smell it!! –Warning H 2 SO 4 causes severe burns Do a positive tests on table salt to test for Chloride ions

Part C Add a small amount of salt to a dry test tube Add 15 drops of distilled water Using a beral pipette add 1 drop of Nitric acid Using a beral pipette add 3 drops of silver nitrate Record observation and answer questions 12 – 13 –Warning HNO 3 causes severe burns Do a positive tests on table salt to test for Chloride ions

Part C In a test tube add 2ml of tap water Using a beral pipette add 1 drop of Nitric acid Using a beral pipette add 3 drops of silver nitrate Record observation and answer questions 14 –Warning HNO 3 causes severe burns Do a positive tests on Cl - ions in tap Do not do procedures 15 or question 15

Part D 1.SO BaCl 2 BaSO 4(S) + 2 Cl - SO 4 -2 ions reacts with Barium chloride (BaCl 2 ) to produce Barium sulfate BaSO 4 (S) Read procedures for part D on pg 70 and fill out 16-17on pg 73

Part D Positive tests for sulfates in Epson salt In a test tube add a small quantity of epson salt Using a beral pipette add 1 or two drops of Sulfuric acid Record observation and answer question 16 Warning Sulfuric causes severe burns

Part D Positive tests for sulfates in Epson salt In a test tube add a small quantity of epson salt Add 1 ml of distilled water Using a beral pipette add 1 or 2 drops of Nitric acid Using a beral pipette add 1 or 2 drops of barium Chloride Record observation and answer question 17 Warning Sulfuric acid causes severe burns

Part E (bleach) NaOCl 4 - ion (bleach) acts like a Cl 2 gas Chlorine gas and Chlorine ion act very differently from each other Chlorine gas can convert iodide salts to iodine giving water and reddish hue

Part E (bleach) Positive tests for Iodide Salts NaOCl 4 ion (bleach) reacts with iodine salts to form iodine (Cl 2 ) (aq) + 2I - (I 2 ) (aq) + 2 Cl -

Part E (Bleach) Positive tests for chlorine in bleach In a test tube add a small quantity of Iodine salt Add 1 ml of distilled water Using a beral pipette add 5 drops of bleach Add a few drops of mineral oil Record observation and answer question 18 Warning Bleach is corrosive

Part E (iodide salts) Positive tests for Iodide Salts iodide salts react with silver to form silver iodide, a pale yellow precipitate AgNO 3 aq) + I - (AgI) (s) + NO 3 -

Part E (iodide salts) Positive tests iodide salts In a test tube add a small quantity of sodium iodide Add 1 ml of distilled water Using a beral pipette add 1 drops of Nitric acid Using a beral pipette add 3 drops of silver nitrate Record observation and answer question 19 Nitric acid is corrosive

Part E (iodide salts) Must be done in hood In a test tube add a small quantity of sodium iodide In the hood using a beral pipette add 1 drops of Slfuric acid Record observation and answer question 20 Sulfuric acid is corrosive

Part F (Unknowns) Determine the type of ion your is unknown is based on the results of a positive test with H 2 SO 4 based on table 7.1 on page 71 You solid unknown will contain one of the following ions –CO 3 -2, Cl -,SO 4 -2, I -

Part F (? ions) In a test tube add a small quantity of your unknown compound Using a beral pipette add 1 drops of Sulfuric acid Record observation and based on table 7.1 answer question 21 Warning Sulfuric acid is corrosive

Due next week Pgs 73 – 74 omit page 75 Pre Quiz on lab 8