Solutions Properties of Water Preparing Solutions

Water Most common solvent A polar molecule O  - a hydrogen bond H  +

Hydrogen Bonds Attract Polar Water Molecules

Solute and Solvent Solutions are homogeneous mixtures of two or more substances Solute The substance in the lesser amount Solvent The substance in the greater amount

Nature of Solutes in Solutions Spread evenly throughout the solution Cannot be separated by filtration Can be separated by evaporation Not visible, solution appears transparent May give a color to the solution

Types of Solutions air O 2 gas and N 2 gas gas/gas soda CO 2 gas in water gas/liquid seawater NaCl in water solid/liquid brass copper and zinc solid/solid (alloy)

Solute and Solvent Identify the solute and the solvent. A. brass: 20 g zinc + 50 g copper solute= 1) zinc 2) copper solvent = 1) zinc 2) copper B. 100 g H 2 O + 5 g KCl solute = 1) KCl 2) H 2 O solvent = 1) KCl 2) H 2 O

Solution A. brass: 20 g zinc + 50 g copper solute= 1) zinc solvent = 2) copper B. 100 g H 2 O + 5 g KCl solute = 1) KCl solvent = 2) H 2 O

Identifying Solutes Identify the solute in each of the following solutions: A. 2 g sugar (1) mL water (2) B mL ethyl alcohol(1) and 30.0 mL of methyl alcohol (2) C mL water (1) and 1.50 g NaCl (2) D. Air: 200 mL O 2 (1) mL N 2 (2)

Solution Identify the solute in each of the following solutions: A. 2 g sugar (1) B mL of methyl alcohol (2) C. 50 g NaCl (2) D. 200 mL O 2 (1)

“Like dissolves like” A ____________ solvent such as water is needed to dissolve polar solutes such as sugar and ionic solutes such as NaCl. A ___________solvent such as hexane (C 6 H 14 ) is needed to dissolve nonpolar solutes such as oil or grease.

Is it soluble? Which of the following solutes will dissolve in water? Why? 1) Na 2 SO 4 2) gasoline 3) I 2 4) HCl

Solution Which of the following solutes will dissolve in water? Why? 1) Na 2 SO 4 Yes, polar (ionic) 2) gasoline No, nonnpolar 3) I 2 No, nonpolar 4) HClYes, Polar

How does a solution form? Cl - Na + Cl - Na + H2OH2O H2OH2O Cl - solute Dissolved solute Hydration

Writing An Equation for a Solution When NaCl(s) dissolves in water, the reaction can be written as H 2 O NaCl(s) Na + (aq) + Cl - (aq) solid separation of ions in water

Soluble because….. Solid LiCl is added to some water. It dissolves because A. The Li + ions are attracted to the 1) oxygen atom(  -) of water 2) hydrogen atom(  +) of water B.The Cl - ions are attracted to the 1) oxygen atom(  -) of water 2) hydrogen atom(  +) of water

Solution Solid LiCl is added to some water. It dissolves because A. The Li + ions are attracted to the 1) oxygen atom(  -) of water B.The Cl - ions are attracted to the 2) hydrogen atom(  +) of water

Summary