Using pH to Show Strong vs Weak Acids and Bases: Fair Tests and Dilution | Year 12 Chemistry

Full lesson, notes and practice questions: https://hscscience.com.au/subjects/ch... Two bottles, both labelled 0.100 mol/L: one hydrochloric acid, one ethanoic acid. Use a pH meter to show which is strong, with a fair comparison at matched concentration. Then dilute each solution exactly tenfold and watch how far the pH moves: strong acids move about one unit, weak acids much less. Includes variables, validity, reliability and accuracy, a risk assessment and two exam-style questions. 0:00 Opening question 0:25 Test 1: match the concentration 0:54 The routine, from the last practical 1:16 Results at the same concentration 1:37 What the gap means 2:09 Test 2: dilute tenfold 2:36 The dilution results 2:59 Why the strong acid moves about one unit 3:18 Why the weak acid moves only half 3:46 The bases, and a check 4:18 The variables 4:40 Validity, reliability and accuracy 5:08 The risk assessment 5:34 Memory aid 5:46 Practice question 1 6:22 Answer 1 6:47 Practice question 2 7:18 Answer 2 7:45 Decision rule and handoff 8:11 Key notes Chemistry 2017: Year 12 Module 6, Acid/Base Reactions. Syllabus dotpoint (NSW Chemistry Stage 6, 2017, Module 6): "conduct an investigation to demonstrate the use of pH to indicate the differences between the strength of acids and bases (ACSCH102)" Official 2017 course: https://www.nsw.gov.au/education-and-... Prerequisites: How do strength and concentration differ?; Measuring the pH of acids and bases (practical). Next: How do conjugate pairs and amphiprotic species react? #Year12Chemistry #pH #HSCScience