Quick Quiz What are the 6 strong acids?? What are the 6 strong bases??

Give the conjugate acids of the following: 1.HCO NH 3 3.OH - 4.SO 4 -2

Give the conjugate bases of the following: 1.HCO NH 3 3.HSO H 3 PO 4 5.H 2 O

Define A Lewis Base A Bronsted Lowry acid An Arrhenius Acid

15.4 Relative Strengths (659) Table 15.2 p660 compares relative strengths of acids and bases. A reaction normally goes in the direction of the weaker acid & base. The strongest acids have the weakest conjugate bases and vice versa.

Predict the direction of the reaction based on the Table 15.2: (661) SO HCN  HSO CN - H 2 S + C 2 H 3 O 2 -  HC 2 H 3 O 2 + HS -

15.5 Factors affecting acid strength (662):

Polarity The more polar bonds allow protons to be removed easier increasing the acid strength. Across a period electronegatives increase, increasing the polarity and acid strength. H 2 O<HF

Bond strength The larger the atom is which H is bonded to, the weaker the bond and thus a stronger acid. Down a family the radius increases, decreasing the bond strength and increasing the acid strength. HF<HCl<HBr<HI

Oxoacids: H – O – Y For a series of oxoacids of the same structure, differing only in the atom Y, the acid strength increases with the electronegativity of Y. HIO<HBrO<HClO

Multiple oxygen atoms –For a series of oxoacids, (HO) m YO n, the acid strength increases with n. The more O’s the stronger the acid. HClO< HClO 2 < HClO 3 < HClO 4

Polyprotic Acids Strength decreases as protons are lost. HPO 4 -2 < H 2 PO 4 - < H 3 PO 4

HOMEWORK – OK KT? Read p.676 Q odds