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Day 1. Acid-Base. Review of naming acids. Characteristics of Acids & Bases. Acids are Characterized by: . Sour taste color of indicator Release of H 2 gas Reacts with bases salt( ionic compound) & H 2 O. Bases are Characterized by: . Bitter taste Feels slippery
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Day 1 Acid-Base
Acids are Characterized by: • Sour taste • color of indicator • Release of H2 gas • Reacts with bases salt( ionic compound) & H2O
Bases are Characterized by: • Bitter taste • Feels slippery • color of indicator • Reacts with acid salt( ionic compound) & H2O • Conducts electric current ( its an ionic compound)
Ionization • Adding or removing electrons (e-) • Making a cation or anion
Strong Acids • Ionizes completely = breaks up completely • Conducts electric current (remember electrolyte demo & PhET)
Strong Acids Examples: • Hydrochloric Acid (HCl) • Sulfuric Acid (H2SO4) • Nitric Acid (HNO3)
Strong Base • Ionizes completely = breaks up completely • Examples: group 1 hydroxides – sodium hydroxide, potassium hydroxide, etc.
Neutralization Reaction HCl + NaOH NaCl + HOH Strong + Strong Salt + Water Acid Base HNO3 + KOH KNO3 + HOH
Neutralization Reaction Is a double replacement rxn b/w … strong acid + strong base a salt (ionic compound) + water
pH Scale Determining strength of an Acid or Base
pH scale 0-14 • neutral pH = 7.0 • acidic pH <7.0 • basic pH > 7.0
Calculating pH & [H+] pH = -log[H+] Inverse of log10 is 10^( ) [H+] = 10^(-pH)
Calculating pOH & [OH-] pH = -log[OH-] Inverse of log10 is 10^( ) [OH-] = 10^(-pOH)
Relationship between pH & pOH pH + pOH = 14
If molarity is not known, pH can be determined by… • Acid-Base Indicators • pH meter • Titration
Indicator Solutions • Change color depending on pH of test solution
Problems with indicator solutions: • If you have a colored solution • Approx pH value not exact • Temperature affects color
pH meter • consists of a measuring probe • electronic meter: measures & displays the pH reading • have to calibrate probe
Titration • Use Buret, Erlenmeyer flask, indicator • Use M1V1 = M2V2 to determine molarity of unknown
Answer the following questions while watching the video clips: • Where do you read/How do you read a burette? • What hand do you use to swirl the Erlenmeyer flask? • What hand do use to adjust the burette? • When do you know you are getting close to the endpoint? • How is the standard solution added as you get close to the endpoint? • When do you know you have achieved the endpoint?
Titration Video Clip #1 (3:15) • Titration Video Clip # 2 ( 6:07)