# Buffer Solutions

Drill: Determine the pH of 0.25 M HZ. -7 KaHZ = 2.5 x 10 Buffer

Solutions Buffer Solution A solution that resists changes in pH

Buffer Solution Made from the combination of a weak acid & its salt

Buffer Solution Made from the combination of a weak base & its salt

Buffer Examples Mix acetic acid & sodium acetate Mix ammonia & ammonium chloride

Buffer Solution A buffer solution works best when the acid to salt ratio is 1:1

Buffer Solution A buffer solution works best when the base to salt ratio is 1:1

Buffer Solution The buffering capacity of a solution works best when the pH is near the pKa

pKa or pKb pKa = - log Ka pKb = - log Kb Buffer Problems

Calculate the pH of a solution containing 0.10 M HAc in 0.10 M NaAc: Ka = 1.8 x 10-5

Buffer Problems Calculate the pH of 0.10 M NH3 in 0.20 M NH4NO3: Kb = 1.8 x 10-5

Buffer Problems Calculate the pH of a solution containing 0.10 M HBz in 0.20 M NaBz: Ka = 6.4 x 10-5

Buffer Problems Calculate the pH of a solution containing 0.50 M HQ in 0.10 M NaQ: Ka = 4.0 x 10-5

Drill Calculate the pH of a solution containing 0.30 M HZ in 0.10 M

NaZ: Ka = 3.0 x 10-5 Lab Requirements To make accurate measurements, we must have solutions with

accurately measured concentrations Standard Solution A solution with known concentration

2.004 M HCl STD Problems Calculate the mass of KHP (MW = 204.23)

required to make 1.0 L of 0.100 M KHP HendersonHasselbach Eq [A-] pH = pKa + log [HA]

HendersonHasselbach Eq [B+] pOH = pKb+ log [B] Buffer Problems

Calculate the salt to acid ratio to make a buffer solution with pH = 5.0 Ka for HBZ = 2.0 x 10-5

Buffer Problems Calculate the salt to base ratio to make a buffer solution with pH = 9.48 Kb for MOH = 2.0 x 10-5

Calculate the HCO3- to H2CO3 ratio in blood with pH = 7.40 Ka1 for H2CO3 = 4.4 x 10-7 150 ml of 0.10 M NaOH is

added to 100.0 ml of 0.10 M H2CO3. Calculate all. Ka1 for H2CO3 = 4.4 x 10-7 Ka2 for H2CO3 = 4.7 x 10-11

## Recently Viewed Presentations

• Source: JICMAIL, Kantar TNS Q2 2017 to Q1 2018, Addressed advertising, TV, broadband, landline or mobile providers (Special offer or discount and Vouchers/coupons). Base 313. PEOPLE ACT ON OFFERS AND DISCOUNTS THEY. RECEIVE BY MAIL.
• Round Dance - When Food is within 50 meters Waggle Dance - Food is further away. Waggle indicated distance, direction is degrees to from sun. In hive, dance is done vertically, uses gravity. Habitat Selection? Why? Food! Ideal Free Distribution...
• kashi cereal & dipper doodle bar. lunch. bean & cheese quesadilla (V)sesame chicken saladsliced cucumber. breakfasthot egg & cheese breakfast sandwichbanana muffinyogurt & granola. lunch. cheeseburgerchicken caesar saladshredded lettuce &/or tomatoes. breakfastbreakfast burritobagel w/ cream cheesekashi cereal & dipper doodle...
• The Solution Justification: There is no need to perform a costly and time consuming new temperature survey and calibration after repairs that do not affect the temperature tolerance of the furnace. Other recognized industry standards for furnace calibration permit such...
• Alone, mark and solve word problems #1-3 using the markers. Explain how you got your answers to the person sitting next to you. Did you get the same answer? If not, figure out who is correct. In groups of four,...
• Overview of Renal Function: 1) You have two kidneys that clean your blood when you are resting at very high metabolic cost in terms of % cardiac output and O2 demand. 2) Blood wastes, especially toxic nitrogenous ones, are removed...
• The three small group sessions provided aim to help local communities explore some of the themes and issues that will be raised through the Proclaim '15 initiative.They are written in such a way that they are faithful to themes found...
• TG 4w has to deliver a coexistence assurance document to show coexistence with other 802 standards. Content of the coexistence assurance document has already been discussed during the October telephone conference. Latest version of the document is available on mentor.