510 likes | 637 Vues
This guide serves as a thorough review of acid-base chemistry, focusing on the characteristics and naming of acids and bases, their properties, and the neutralization reactions that occur between them. It covers the pH scale, calculation methods, and the use of titration to determine the molarity of unknown solutions. Key concepts, including ionization, strong acids and bases, and various methods for measuring pH, are presented, alongside practical tips for conducting experiments. Perfect for students seeking to deepen their understanding of acid-base interactions.
E N D
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)