1 / 29

Warm-up

Warm-up. What are some properties of acids and bases? According to the Brønsted-Lowry Model, what is the definition of an Acid? A Base? Describe the dissociation of a strong/weak acid. A strong/weak base. Describe the pH scale. What does it mean that the pH scale is logarithmic?

huyen
Download Presentation

Warm-up

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Warm-up What are some properties of acids and bases? According to the Brønsted-Lowry Model, what is the definition of an Acid? A Base? Describe the dissociation of a strong/weak acid. A strong/weak base. Describe the pH scale. What does it mean that the pH scale is logarithmic? What is the type of strong acid in our stomach?

  2. Arrhenius Model of Acids and Bases According to the Arrhenius Model: Acidscontain _____________________ which then dissociate. Basescontains ____________________ which then dissociate. Acids and bases can _____________ electricity because the ______________. Hydrogen (H+) Hydroxide (OH-)

  3. BrØnsted-Lowry Modelof Acids and Bases 5b Acids substances thatare hydrogen-ion ____________. Base substancesthat are hydrogen-ion ____________ Donor Acceptor

  4. True or False. All Bases with a Group 1 Metal (Alkali Metal) are Strong Bases…

  5. If an Acid is strong its Conjugate Base is ________________________. If a Base is a weak base than its Conjugate Acid is __________________.

  6. Complete the following Acid Base Conjugate pairs. The Acid is always first. Complete the equation and label the Conjugate Base (CB) and Conjugate Acid (CA). a) HCO3–(aq) + S2–(aq)  HS–(aq) + CO32–(aq) conjugate acid conjugate base acid base conjugate acid-base pairs b) H2CO3(aq) + OH–(aq)  HCO3–(aq) + H2O(l) acid base conjugate base conjugate acid conjugate acid-base pairs

  7. Complete the following Acid Base Conjugate pairs. Complete the equation and label the Conjugate Base (CB) and Conjugate Acid (CA). c) H3O+(aq) + HSO3–(aq)  H2O(l) + H2SO3(aq) conjugate base conjugate acid acid base conjugate acid-base pairs d) HSO3–(aq) + OH–(aq) + )  H2O(l) + SO32–(aq) conjugate acid conjugate base base acid conjugate acid-base pairs

  8. Water as an Acid and a Base Water is _____________, because it can behave as either an acid or as a base

  9. What is the formula for finding the concentration of H+ and OH-

  10. Strong acid – completely ionized or completely dissociated Weak acid – most of the acid molecules remains intact

  11. Acid Strength A strong acid contains a relatively weak conjugate base. • Common strong acids are • Sulfuric acid, H2SO4 • Hydrochloric acid, HCl • Nitric acid, HNO3 • Perchloric acid, HClO4 Oxyacid– Strong Acids, acidic proton is attached to an oxygen atom

  12. pH Scale 5d Describe the pH scale. What does it mean that the pH scale is logarithmic? • pH is a measure of how much H+ a solution contains. • Lower pH contain more H + and less OH- • Higher pH contain less H + and more OH- • The scale is logarithmic, meaning an increase of 1 on the scale is actually a 10x increase! • A pH of 2 is actually 100x as acidic as a 4.

  13. The pH Scale pOH scale • pOH = log [OH] • pH + pOH = 14.00

  14. Measuring pH Indicators – substances that exhibit different colors in acidic and basic solutions • In an acid solution the indicator will be in the HIn form. • In a basic solution the indicator will be in the In form. • Other methods • Indicator paper • pH meter

  15. You Try #2 • Calculate pH for a solution that has [OH-] = 1.0 x 10-5 M. pH = 9.00

  16. You Try #3 • Calculate pOH for a solution that has [H+] = 1.0 M pOH = 14.00

  17. You Try #4 • Calculate pOH for a solution that has a pH = 6 pOH = 8

  18. You Try #5 • Calculate pH for a solution that has a pOH = 7 pH = 7

  19. You Try #6 • Calculate pH for a solution that has a pOH = 7.56 pH = 6.44

  20. You Try #7 • Calculate [OH-] for a solution that has a pH = 6.20 pH = 1.6 x 10-8

  21. You Try #8 • Calculate [OH-] for a solution that has a pH = 8.20 pH = 1.6 x 10-6

  22. You Try #9 • Calculate pH for a solution that has a [OH-] = 2.3 x 10-5 pH = 9.36

  23. Buffers 5g • Buffers are substances that absorb or release H+ as needed to regulate the pH. • You have a buffer in your blood called bicarbonate • If the pH falls, it absorbs the extra H+ • If the pH rises, it releases some H+ • It keeps your blood neutral! H2CO3 H+ + HCO3-

  24. Neutralization Reactions Both produce Salts when reacted with each other Neutralization reaction: An acid and a base react to form a salt and water. Salt: any ionic compound (metal & non-metal) HCl(aq) + NaOH(aq) →NaCl(aq) + H2O(l) ACID BASE SALT

  25. Salts Made up of a metal and a nonmetal. When dissolved in water, salts conduct electricity.

  26. Acid-Base Titrations Titration – delivering a measured volume of a solution of known concentration into the solution being analyzed Buret – device used for accurate measurement of the delivery of a liquid Equivalence Point) – the point at which neutralization occurs.

  27. Neutralization Practice MaVa = MbVb • Determine the volume of 0.100 M NaOH needed to titrate 50.0mL of 0.200 M HNO3 • We need equals moles of H+ and OH- • HNO3 is a strong acid --> H+ • NaOH is a strong base --> OH- • So…we get 0.0500L x 0.200 M H+ = Vol x 0.100 M OH- Volume = 0.100L or 100 ml NaOH

  28. Neutralization Practice #1(Your Turn) MaVa = MbVb • Determine the volume of 0.250 M KOH needed to titrate 25.0mL of 0.150 M HCl • We need equals moles of H+ and OH- Volume = 15.0 ml or 0.0150 L KOH

  29. Neutralization Practice #2(Your Turn) MaVa = MbVb • Determine the volume of 0.200 M NaOH needed to titrate 75.0mL of 0.250 M HNO3 Volume = 93.8 ml or 0.0938 L KOH

More Related