Gas Forming Rxns, Driving Forces, and Redox Chapter 5 part 3

Gas Forming Reactions  Carbonate (CO 3 2- )/bicarbonate (HCO 3 - ) react with acid (H + ) to make CO 2 and H 2 O  NaHCO 3 (s) + HCl --> Net ionic: NaCl + CO 2 (g) + H 2 O  NaHCO 3 + H + --> Na + + CO 2 (g) + H 2 O

Gas Forming Reactions  Sulfite (SO 3 2- ) reacts with acid (H + ) to make SO 2 and water

“Driving Forces” The formation of a special product moves these reaction forward:  Precipitation - solid  Acid-Base - water  Gas-Forming - gas molecule

“Driving Forces”  Product or Reactant Favored?  2Na 3 PO 4 + 3Ni(NO 3 ) 2 --> 6 NaNO 3 + Ni 3 (PO 4 ) 2  CaCl 2 + H 2 O --> Ca(OH) 2 + HNO 3

“Driving Forces”  The transfer of e- moves redox reactions forward  An oxidized substance provides e- to the reduced substance

Redox Reactions  Oxidation and Reduction occur together  OILRIG  Oxidation  Oxidation - “loss of e-”  the oxidation # (charge) element gets higher  Reduction  Reduction - “gain of e-”  the ox # of element gets lower

Redox Reactions  HCl + Zn --> ? + ?  Show the movement of e-

Recognizing REDOX  First assign ox # to each element  The charges must change in a redox rx  If element ends up with a higher ox# its oxidized  If element ends up with a lower ox# it is reduced

Oxidation Numbers  Refer to the handout

Assign Ox# to the Element NH 3 CaCl 2 ClO 4 - ClO 3 - H 3 PO 4 C3H8C3H8C3H8C3H8 Oxidation number of F in HF?