Warm-Up 12/16/2016 A mixture of gases (NO2,CO2, SO2) is collected in a bottle. The partial pressure of NO2 is 1.25 atm, and the partial pressure of CO2 is 2.63 atm. If the total pressure of the gases is 11.20 atm, what is the partial pressure of SO2? A) 2.89 atm B) 7.32 atm C) 9.23 atm D) 11.20 atm

Example Problem 1. If [H+ ] = 1 x 10-5, what is the concentration of [(OH-)]? Begin 5th, 7th 5-1-2000

pH Scale The pH scale was developed in an effort of compare the strengths of acids and bases The pH scale runs from 0-14 pH < 7 are acidic pH = 7 are neutral pH > 7 are basic

Mathematical Definition of pH pH (potential of Hydrogen) is defined as the negative logarithm of the hydrogen-ion concentration pH = - log [H+]

Example What is the pH of a solution in which [H+] = 3.45 x 10-5? Is the substance acidic, basic, or neutral?

Additional pH Examples Calculate the pH values. Determine if each solution is acidic, basic, or neutral. A. [H+] = 1 x 10-7 B. [H+] = 6.7 x 10-11 C. [H+] = 0.1 D. [H+] = 8.54 x 10-9

Find the Following pH’s and tell if it is acidic, basic or neutral Practice Find the Following pH’s and tell if it is acidic, basic or neutral [H+] = 2.345 x 10-4 [H+] = 1 x 10-11 [H+] = 4.5 x 10-7

pH Values and Concentration If the pH value is known the hydrogen ion concentration can be determined [H+] = 10-pH

Example Problem # 1 What is the hydrogen ion concentration if pH = 3.4 pH = - log [H+] 3.4 = - log [H+] 10-3.4 = [H+] 3.98 x 10-4 = [H+]

Example Problem # 2 What is the Hydrogen Ion Concentration if the pH equals 8.75? Answer = [H+] = 1.78 x 10-9

pOH( Potential of Hydroxide Ions) pOH measures the amount of hydroxide ions pOH is used to measure basicity pOH = - log [OH-] pH + pOH = 14

Practice What is the pOH of a solution that contains 3.45 x10-5 [OH-]? What is the substance’s pH?

Complete the following chart

Complete the following chart

Practice Complete the following chart 15

Practice Problems Determine if each of the following solutions is acidic, basic, or neutral: a. [H+] = 6 x 10-10 b. [OH-] = 3 x 10-2 c. [H+] = 2 x 10-7 d. [OH-] = 1 x 10-7 Begin 1st 5-1-2000, 3rd

What is the pH and the pOH of the following? 1) 0.001 M HCl 2) 0.0034 M NaOH 3).0025 M H2SO4 4) .00725 M Ca(OH)2

Molarity A measurement of the concentration of a solution Molarity (M)= is equal to the moles of solute (mol) per liter of solution M = mol/ L

Practice Calculate the molarity of a solution prepared by mixing 1.5 g of NaCl in 500.0 mL of water.