GET READY FOR YOUR QUIZ!
• You need
•
•
•
•
A periodic table
Solubility rules
A calculator
A pen/pencil
• When you’re done
• Put your quiz in the basket
• Bring me your book problems from the weekend
• Tonight’s homework
• Notes on section 4.3
• Read through the slides (I will give them to you when you show me your
homework)
• If you HAVEN’T taken 1st year chemistry, reaction balancing and
classification
• If you have and want a refresher, it is an optional assignment
• Finish your copper oxide lab report
WARM-UP
• Please have your notes and practice problems out for me to
check.
• Write a molecular equation for the gas-evolution
reaction that occurs when you mix aqueous
hydrobromic acid and aqueous potassium sulfite.
• Write a net ionic reaction for the reaction that
occurs when you mix hydriodic acid with calcium
sulfide.
TYPES OF AQUEOUS
REACTIONS
• Precipitation reactions (you should be an expert
on these now!!)
• Acid-Base reactions
• Gas-Evolution Reactions
ACID BASE REACTIONS
• An acid reacts with a base to form water and an ionic salt
• Remember that salt is a generic term in chemistry –
not just NaCl!
• Acid provides H+
• Base provides OH• Example: nitric acid reacts with lithium hydroxide
• HNO3 + LiOH –> H2O + LiNO3
ACID BASE REACTIONS
• Titration – a lab procedure where a substance of known
concentration is reacted with another substance in a solution
of unknown concentration in the presence of an indicator
• Equivalence point – the point in the titration when the
number of moles of OH- equals the number of moles of H+
• Indicator – a pH dependent dye that allows the chemist to
identify the equivalence point by a color change
POLYPROTIC ACIDS
• An acid that provides more than one hydrogen
ion per molecule is called polyprotic
• Examples: H2SO4 (diprotic), H3PO4
• Write a balanced equation for the reaction
between sulfuric acid and sodium hydroxide
POLYPROTIC ACIDS
• An acid that provides more than one hydrogen
ion per molecule is called polyprotic
• Examples: H2SO4 (diprotic), H3PO4
• Write a balanced equation for the reaction
between sulfuric acid and sodium hydroxide
• H2SO4 + 2NaOH –> 2H2O + Na2SO4
H+ OR H3O+?
• A hydrogen ion is a single proton
• In solution, H+ ions will pair up with water molecules to
form H3O+
• This is called the hydronium ion
• In reality, it is more accurate to write your equations
using the hydronium ion
• In practice, it does not matter (neither Ms. Dandridge
nor the College Board cares which one you use)
GAS-EVOLUTION
REACTIONS
• Two aqueous solutions mix to form a gaseous product
• Bubbles!
• Common gases you should know
• H2S
• H2CO3 –> H2O + CO2
• H2SO3 –> H2O + SO2
• NH4OH –> H2O + NH3
GAS-EVOLUTION
REACTIONS
• Write a balanced equation (including states of
matter!) for the reaction between hydrochloric
acid and sodium bisulfite.
HOMEWORK
• Copper oxide lab due tomorrow!
• Anyone who HASN’T taken 1st year chemistry – basic
reaction type and balancing practice is required
• Also available for anyone else who wants a refresher!
• Tomorrow we will practice these reaction types