Science 3101 Curriculum Guide 2005-06

Unit 3 - MixturesOutcomes3.3.2 Describe, in generalterms, the pH scale as anindicator of acidity or basicity.3.3.3 Investigate the pH ofcommon substances.Notes for Teaching and LearningStudents are required to work through the DiscConnect, Acids and Bases, where they do a laboratorysimulation that runs a series of tests on household itemsto determine which are acids and which are bases. Theyshould be provided with a copy of ICT 4-3 to completeas they work on the computer. They will print out acopy of the Certificate of Completion to be includedwith their notes.Students can have the opportunity to gain hands onexperience in identifying common household mixturesass acids and bases and determining their pH bycompleting Investigation 4-B, Acids and Bases AroundYou, pages 66 - 68. BLM 4-5 can be used to recordobservations.For hands on experience in seeing how pH andconductivity are related, students could also be asked tocomplete the activity outlined on BLM 4-4,Conductivity and pH.Students should understand that small changes in pHvalue indicate very large changes in level of acidity(i.e., pH scale is logarithmic). Therefore each decreaseof 1.0 on the pH scale means a ten-fold increase in theamount of acid present. For example, a solution withpH=3 is 10 times more acidic than one that is pH=4 and100 times more acidic than one that is pH=5.Curriculum Guide Page 8Science 3101