Unit 4 Part 2 Solutions

Components of a Solution  A solution is composed of two or more pure substances, one of which is a solvent and the other a solute.

Components of a Solution  A cup of instant coffee is the ____________, the hot water is the ____________, and the instant coffee is the ____________.  Solvent Solution Solute

Components of a Solution  Solutions in which water is the solvent are called aqueous solutions.

Water as a Solvent  Most covalent liquids are only able to dissolve other covalent compounds; water can dissolve both ionic and covalent compounds.

Water as a solvent

 The attraction of water dipoles for ions pulls ions out of a crystalline lattice and into aqueous solution.

Solutions:  A saturated solution is a solution that contains the maximum amount of solute dissolved in a solvent. A supersaturated solution is a solution where conditions have been changed to allow more solute to dissolve than would at room temperature (this is done by heating the solvent or solution).

Solutions:  When the solvent and solutes are liquids we can use the terms miscible and immiscible. Miscible means that the two liquids will mix together, and immiscible means that the two liquids will not dissolve in one another.

Solutions:  Sometimes when we mix two dissolved salts together, we end up with a precipitate. This is because a new ionic compound is formed that is insoluble in water.

Solutions:  We can use solubility charts or solubility tables to determine if a solid will be formed. IonSolubilityExceptions NO 3 – solublenone ClO 4 – solublenone Cl – soluble except Ag +, Hg 2 2+, *Pb 2+ I–I– solubleexcept Ag +, Hg 2 2+, *Pb 2+ SO 4 2- soluble except Ca 2+, Ba 2+, Sr 2+, Hg 2+, Pb 2+, Ag + CO 3 2- insoluble except Group IA and NH 4 + PO 4 3- insoluble except Group IA and NH 4 + OH – insoluble except Group IA, *Ca 2+, Ba 2+, Sr 2+ S 2- insoluble except Group IA, IIA and NH 4 + Na + solublenone K+K+ solublenone NH 4 + solublenone

Solutions  Ex. If we mix sodium ions with hydroxide ions will a precipitate form?  Ex. If we dissolved sodium hydroxide in calcium chloride, will a precipitate form?  2NaOH + CaCl 2  2NaCl + Ca(OH) 2

Solutions  Ex. Calcium nitrate with sodium carbonate  Ca(NO 3 ) 2 + Na 2 CO 3  CaCO3 + 2NaNO3  Ex. Silver Perchlorate and Calcium Iodide  Ca(ClO 4 ) 2 (________) and AgI (__________)

Demonstrations IonSolubilityExceptions NO 3 – solublenone ClO 4 – solublenone Cl – soluble except Ag +, Hg 2 2+, *Pb 2+ I–I– solubleexcept Ag +, Hg 2 2+, *Pb 2+ SO 4 2- soluble except Ca 2+, Ba 2+, Sr 2+, Hg 2+, Pb 2+, Ag + CO 3 2- insoluble except Group IA and NH 4 + PO 4 3- insoluble except Group IA and NH 4 + OH – insoluble except Group IA, *Ca 2+, Ba 2+, Sr 2+ S 2- insoluble except Group IA, IIA and NH 4 + Na + solublenone K+K+ solublenone NH 4 + solublenone