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