120 likes | 196 Views
Explore how ionic compounds dissolve, dissociate, and form precipitates in aqueous solutions. Learn about strong and weak electrolytes, colligative properties, and the impact of different compounds on solution properties.
E N D
Compounds in Aqueous Solutions • Dissociation – separation of ions when an ionic compound dissolves
Compounds in Aqueous Solutions cont. • Soluble Na, K, and NH4+ compounds Nitrates, acetates, chlorates Chlorides --- except Ag, Hg, Pb Sulfates --- except Ba, Sr, Pb • Insoluble Carbonates, phosphates, silicates --- except Na, K, NH4 + Sulfides --- except Ca, Sr, Na, K, NH4 + Hydroxides --- except Group 1, Ba, Sr
Compounds in Aqueous Solutions cont. • Write balanced chemical equation and identify the precipitate (insoluble product) when these solutions are mixed. • Precipitate designated as (s) or ( ); (aq) means dissolved in water • Na2CO3 and CaCl2 • AgNO3 and NaCl • Pb(NO3)2 and Kl ( a yellow precipitate is observed)
Compounds in Aqueous Solutions cont. • Ionization – formation of ions when a molecular compound dissolves
Compounds in Aqueous Solutions cont. • Hydronium Ion (H3O+)
Compounds in Aqueous Solutions cont. • Hydronium Ion is formed when a hydrogen ion attaches to a water molecule. (we will simply use H+ and not show H2O)
Electrolytes • Strong Electrolytes – all the compound which dissolves to form ions • Weak Electrolytes - only a small amount of the compound which dissolves forms ions
Colligative Properties • Ways that a solution is different then pure H2O • Lower vapor pressure (evaporates slower) • Lower freezing point • Higher boiling point • Colligative properties – properties which depend on the number of particles in a solution: the above are colligative properties • The amount of change is increased if more of the solute is dissolved
Colligative Properties • An ionic compound (electrolyte) produces more particles in the solution than the same number of moles of a molecular compound (nonelectrolyte).
Colligative Properties • C12H22O11 (s) C12H22O11 (aq) 1 mol 1 mol of particles • NaCl (s) Na+ (aq) + Cl- (aq) 1 mol 1 mol 1 mol total of 2 mol of particles • CaCl2 (s) Ca+ (aq) + 2 Cl- (aq) 1 mol 1 mol 2 mol total of 3 mol of particles
Colligative Properties • Sodium Chloride causes twice as much change as sucrose • Calcium Chloride causes 3 times and much change as sucrose