catalyst
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Catalyst. 1 . What is the difference between a strong base and a weak base? 2 . What does it mean fo r something to dissociate? 3 . What ar e the units of Molarity? What does Molarity mean?. End. Justify – TPS. - PowerPoint PPT PresentationTRANSCRIPT
Catalyst1. What is the difference between a strong base and a weak base?2. What does it mean for something to dissociate?3. What are the units of Molarity? What does Molarity mean?
End
Justify – TPS
• Why did the solution of NaOH change colors the way that it did once I mixed the two?
LECTURE 6.4 – ACID/BASE TITRATIONS
Today’s Learning Targets• 6.6 – I can calculate the concentration of
an unknown acidic solution using a titration.
Today’s Focus Question• I have my acid that I need to dispose of
my body with, but how do I know the concentration so as to ensure it is strong enough to dissolve everything?
What are indicators?
I. Acid/Base Indicators• Indicators – Some compounds change
color depending on pH.• Therefore, these compounds tell us the
general pH of our solution based their color
How are indicators used in titrations?
I. Titrations• Often times, we have
solutions of unknown concentrations
• Titration – The controlled addition of solution of known concentration/volume to a solution of known volume, but unknown concentration.
Acid/Base of known volume and unknown concentration with an indicator.
Acid/Base of known volume and concentration.
II. Equivalence Point• Equivalence Point – The
point at which the two solutions used in a titration are present in equal amounts.
• We use indicators to spot this point
• For this class, always at pH = 7
• Moles of acid = moles of base at this point
How are titrations used to calculate concentrations?
I. Calculating Concentration for Titrations
Volume of base that was added in titration
Molarity of base Volume of
unknown acidMole Ratio from balanced chemical reaction
Class Example
• If it takes 0.540 L of 0.1 M NaOH to neutralize 0.125 L of an HCl solution, what is the concentration of the HCl?
Class Example
• If it takes 0.140 L of 0.051 M HNO3 to neutralize 0.225 L of an LiOH solution, what is the concentration of the HNO3?
Table Talk• It takes 2.540 L of 1.1 M HBr to neutralize 1.25 L
of an KOH solution, what is the concentration of the HBr?
Quiz
• You have 15 minutes to complete this quiz.
Around the World
• There are 6 questions for you to try around the room.
SUMMARIZE
Closing Time• Worksheet 6.3 is due on Thursday/Friday