Download presentation
Presentation is loading. Please wait.
Published byJarod Ridley Modified over 10 years ago
1
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions Dr. Ron Rusay Spring 2002
2
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions There are several general types: 1) Precipitation: An insoluble salt forms from the addition of solutions. (Refer to Solubility Rules) 2) Acid-Base Reactions (Neutralization) generally produces a salt plus water 3) Oxidation-Reduction (Redox) there is a change in oxidation numbers between reactants and products
3
Solution Test Apparatus for Electrolytes
4
© Copyright 1995-2002 R.J. Rusay Electrolytes Aqueous solutions can be categorized into 3 types: non-electrolytes, strong electrolytes or weak electrolytes based on their ability to conduct electricity. A solution must have ions to conduct. Pure Water does not conduct. Aqueous solutions can be tested for conductivity which will determine the degree of ionization of the solutes. It is possible to have full or partial ionization.
5
© Copyright 1995-2002 R.J. Rusay Electrolytes Almost all ionic compounds and a few molecular compounds are strong electrolytes. Several molecular compounds are weak conductors, most are non-conductors. Conductivity is directly related to the amount of ionization, i.e. ions in solution. Table salt, sodium chloride, is completely ionized: NaCl (s) + H 2 O (l) ---> NaCl (aq) ---> 0.10MNa + (aq) + Cl - (aq) 0.00M 0.10M 0.10M
6
© Copyright 1995-2002 R.J. Rusay Electrolytes � Concentrations: � 2 2 � CaCl 2 (s) + H 2 O (l) ---> CaCl 2(aq) ---> 0.10MCa 2+ (aq) + 2 Cl - (aq) 0.00M 0.10M 0.20M
7
© Copyright 1995-2002 R.J. Rusay Electrolytes Sugars like sucrose are non-ionic, molecular compounds that dissolve but produce no ions. C 12 H 22 O 11 (S) + H 2 O (l) ----> C 12 H 22 O 11 (aq) Some molecular compounds like acetic acid ionize partially (dissociate) in water HC 2 H 3 O 2 (l) + H 2 O (l) H 3 O + (aq) + 0.1000M C 2 H 3 O 2 - (aq) 0.9987M0.0013M
8
© Copyright 1995-2002 R.J. Rusay Aqueous Bases Any compound that accepts a proton is a base. The common bases are group IA & IIA metal hydroxide compounds. They are strong bases, dissociating completely in water. An example of a weak base is ammonia. NH 3 (g) + H 2 O (l) NH 3 (aq) NH 4 + (aq) + OH - (aq)
9
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions: Neutralization Net Ionic Equations HCl (aq) + NaOH (aq) ---> NaCl (aq) + H 2 O (l) ___________________________________________________ � � HCl (aq) ---> H + (aq) + Cl - (aq) � � NaOH (aq) ---> Na + (aq) + OH - (aq) � � NaCl (aq) ---> Na + (aq) + Cl - (aq) ________________________________________________ Na + (aq) + OH - (aq) + H + (aq) + Cl - (aq) ---> Na + (aq) + Cl - (aq) + H 2 O (l) _______________________________________________________ H + (aq) + OH - (aq) ---> H 2 O (l)
10
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions: Precipitation Net Ionic Equations 50mL of a 0.1M solution of sodium sulfate is mixed with 50mL of a 0.2M solution of silver nitrate. What is the result? Molecular Equation: ?Na 2 SO 4(aq) + ?AgNO 3(aq) ---> ?Na 2 SO 4(aq) + ?AgNO 3(aq) ---> ?Ag 2 SO 4(s) + ?NaNO 3(aq) 1 2 12
11
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions: Precipitation Net Ionic Equations Na 2 SO 4(aq) + 2 AgNO 3(aq) -->Ag 2 SO 4(s) + 0.1M0.2M 2 NaNO 3(aq) Ionic Reaction (Reactants): Na 2 SO 4(aq) 2 Na + (aq) + SO 4 2- (aq) 2 AgNO 3(aq) 2 Ag + (aq) + 2 NO 3 1- (aq) 2 AgNO 3(aq) 2 Ag + (aq) + 2 NO 3 1- (aq) 2 Na + (aq) + SO 4 2- (aq) + 2 Ag + (aq) + 2 NO 3 1- (aq) 0.2M0.1M0.2M 0.2M 0.2M0.1M0.2M 0.2M
12
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions: Precipitation Net Ionic Equations Na 2 SO 4(aq) + 2 AgNO 3(aq) -->Ag 2 SO 4(s) + 0.1M0.2M 2 NaNO 3(aq) Ionic Reaction (Products): 2 NaNO 3(aq) 2 Na + (aq) + 2 NO 3 1- (aq) Ag 2 SO 4(s) Does not dissolve (ionize) Ag 2 SO 4(s) Does not dissolve (ionize) 2Na + (aq) + 2NO 3 1- (aq) + Ag 2 SO 4(s) 0.2M 0.2M solid 0.2M 0.2M solid
13
© Copyright 1995-2002 R.J. Rusay Aqueous Reactions: Precipitation Net Ionic Equations Na 2 SO 4(aq) + 2 AgNO 3(aq) -->Ag 2 SO 4(s) + 2 NaNO 3(aq) Overall Ionic Reaction: 2Na + (aq) + SO 4 2- (aq) +2Ag + (aq) + 2NO 3 1- (aq) 2Na + (aq) + Ag 2 SO 4(s) + 2NO 3 1- (aq) Net Ionic Equation: (Subtract Spectator Ions) 2Ag + (aq) + SO 4 2- (aq) Ag 2 SO 4(s) = M Na2SO4 xV Na2SO4 / 1:1 stoichiometry = 0.10M x 0.050 L/ 1 = 0.0050 mol How many moles?
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.