Presentation on theme: "PH and Titration Notes Chemistry. pH measure of the strength of acids and bases pH = power of hydrogen pH = -log [H + ] logarithmic scale – so."— Presentation transcript:
pH measure of the strength of acids and bases pH = power of hydrogen pH = -log [H + ] logarithmic scale – so when you change a number on the scale, you change by a factor of 10 pH 3 is 10 times less acidic than pH 2 pH 1 is 100 times more acidic as pH 3
pOH measures strength of the hydroxide ion pOH = -log [OH - ] highest value of pH or pOH = 14 lower value of pOH = stronger base pH + pOH = 14 if find one of the values, then subtract from 14 to find the other example: if pH is 3, then pOH is 11 (14-3 = 11)
Neutralization reaction between an acid and a base in which their acidic and basic properties disappear Acid + Base Salt + Water salt = metal and a non-metal ex. HCl + NaOH NaCl + H 2 O ex. HCl + Ca(OH) 2 CaCl 2 + H 2 O
Titration technique used by chemists to determine the unknown concentration of a substance using a neutralization reaction uses an indicator to tell when reaction has reached neutralization indicator – chemical that is one color in an acid and another color in a base end point – the point in the reaction when neutralization has occurred and the indicator changes color
Acid-Base Indicators An acid – base indicator changes color when it is in a solution of a certain pH. Red litmus paper turns blue and is used as an indicator of a basic solution that would have a pH above 7. Blue litmus paper turns red and is used as an indicator of an acidic solution that would have a pH below 7. Phenolphthalein is also a common kind of acid – base indicator. It turns clear in an acid and pink in a base. http://www.middleschoolchemistry.com/multimedia/ chapter6/lesson8#proton_transfer_illustration http://www.middleschoolchemistry.com/multimedia/ chapter6/lesson8#proton_transfer_illustration
Titration Equation when reaction in titration is neutral, moles of acid = moles of base moles = molarity (M) x volume (V) so use the equation: Moles Acid = Moles Base M 1 V 1 = M 2 V 2
Titration Example 1 What is the molarity of a CsOH solution if 30.0 mL of the solution is neutralized by 26.4 mL of a 0.250 M HBr solution?
Titration Example 2 What is the molarity of a nitric acid solution if 43.33 mL of a 0.100 M KOH solution is needed to neutralize 20.0 mL of HNO 3 ?
Titration Example 3 What is the concentration of a household ammonia cleaning solution if 49.9 mL of a 0.59 M HCl solution is required to neutralize 25.0 mL of ammonia solution?
Titration Example 4 A titration of 50 mL of an unknown concentration of NaOH solution uses a 0.5 M HCl solution. The buret containing HCl initially reads 49.8 mL and reads 22.5 mL after the end point is reached. What is the molarity of the NaOH solution?