1 The Scientific Method

PROCEDURES:ACTIONS:I. CHEMICAL REACTION MYSTERY1. Obtain a quart-sized zip-close plastic bag.2. Place 1 spoonful of sodium bicarbonate 1 (NaHCO 3 ) into one of thecorners of the plastic bag. Observe and record its properties 2 on thereport sheet (Box I2).3. Place 2 spoonfuls of calcium chloride 3 (CaCl 2 ) in a different cornerof the same bag. Note and describe the properties 2 of the calciumchloride (Box I3).4. Mix the sodium bicarbonate and calcium chloride together by gentlytipping the bag back and forth.5. Measure 10 mLs of 0.04% phenol red solution and pour into a smalltest tube or vial. Note and describe the properties. (Box I5). 46. Without spilling, set the small test tube or vial inside the zip-lockbag. Without spilling the vial, carefully squeeze most of the air outof the bag and seal it. 57. With all of your ingredients sealed inside the bag now spill thephenol red solution by tipping over the tube. Mix the contents ofthe bag. This is Trial 1.8. Observe the chemical reaction occurring between the 4 substancesinside the bag and record your observations of the 3 significantchanges. (Box I8).9. Perform further trials by making new combinations of the 4 possiblesubstances to determine which substances are responsible for eachof the 3 changes you observed. 6 Change only what combinationsubstances you use in the reaction. Do not change the amount ofeach substance. 710. Record your observations for each trial in the results column of thereport sheet.NOTES:1 Sodium Bicarbonate iscommon baking soda.2 Physical properties mayinclude its state (whether it issolid, liquid, or gas), its color,its odor, etc. If it is a solidnote the kind of granules orcrystals present that mightdistinguish it from othersolids.3 Calcium Chloride is acommonly used salt formelting ice on frozensidewalks.4 Phenol red solution is acombination of phenol red (asolid) and water.5 The bag must be sealed wellso that no liquid or gasescapes.6 Use the same bag but cleanthe zip-close bag and vialbefore doing a newexperiment. Rinse the bagwith water several times andpour the water down the drain.Dry the inside of the bag witha paper towel. Do notpuncture the bag. Rinse thetube or vial.7 Phenol Red solution alwayscontains water so you willnever use phenol red withoutusing water as well. However,you can use water withoutusing phenol red by simplyusing deionized water as oneof your reagents.11. Do as many trials as needed to discover the minimum combinationof substances needed to produce each change.II. CONCLUSIONS12. Make conclusions to answer the questions as to the minimumsubstances necessary to produce each property change.13. Clean-up by rinsing the zip-close bag in the sink.10CH104 Lab 1: The Scientific Method (F14)