Classifying Solutions Essays - Solutions, Equilibrium Chemistry

Classifying Solutions Essays - Solutions, Equilibrium Chemistry Classifying Solutions Types of Solutions Gas Solid/Gas Liquid/Gas Gas Solid Solid/Solid Liquid/Solid Gas Liquid Solid/Liquid Liquid/Liquid Gas Solution-a liquid mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent) Solvent- A substance that can dissolve another substance, or in which another substance is dissolved into Solute-The minor component in a solution, dissolved in the solvent Aqueous-contains water Alloy-a solid solution or two or more metals Solubility-The maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature Saturated Solution-a solution that cannot dissolve more solute (contains maximum amount of solute at which the solution exists) Unsaturated Solution-a solution that could dissolve more solute (contains less solute than the maximum amount possible is dissolved in the solution) Supersaturated Solution-a solution that contains more dissolved solute than a saturated solution at the same temperature Determining the type of solution -Add a seed crystal of solute -Dissolves= unsaturated -Does not dissolve= saturated -Begins to crystallize= supersaturated Solubility Expressed in grams of solute per 100g of solvent Solute Solubility (g solute/100g solvent)Qualitative Solubility description Less than 0.1Insoluble 0.1>1Slightly Soluble 1-10Soluble 10Very soluble e.g. A 3.20g sample of a salt dissolves in 9.10g of water to give a saturated solution at 25*C. What is the solubility (in g salt/100g of water) of the salt? Solute = 3.20gSalt = x _ Solvent 9.10gH2O 100gH2O x=3.20gSalt(100gH2O) 9.10gH2O x=35.2g Factors that Affect Solubility Forces that act between the particle of the substances in solutions: -forces that attract particle of the solute to each other -forces that attracts particle of the solute to particles of the solvent -forces that attract particles of the solvent to each other Solubility in Water -The polar nature of water molecules enables water to dissolve a wide range of solutes -Most ionic compounds are soluble in water 1.Electrical attraction between the polar water molecules and the ions pulls ions from the surface of the solute 2.Polar water molecules surround the separated ions in a process called hydration, and ions disperse uniformly in solution Polar compounds dissolve in water Nonpolar compounds dont dissolve in water Nonpolar compounds can dissolve in nonpolar solvents Conductivity of Aqueous Solutions Solutions of ionic compounds can conduct electricity. Temperature and Solubility (Solid in Liquid) For most ionic solids, solubility increases as temp increases. Temperature and Solubility(Liquid in Liquid, Gas in Gas) Temperature change has little effect on the solubility of one liquid in another one or one gas in another Temperature and Solubility(Gas in Liquid) The solubility of a gas in a liquid decreases as the temperature increases Pressure and Solubility(Gas in Liquid) The solubility of a gas in a liquid is directionally proportional to the pressure of that same particular gas above the liquid Factors that Affect Rate of Dissolving -agitation or mixing(stirring) -temperature increases -increased surface area of the solute Concentrations of Solutions as a % Concentration-the ratio of the quantity of solvent or the quantity of solution Concentrated-having a high ratio of solute to a solution Dilute-having a low ratio of solute to solution % (Mass/Volume) -a ratio of the mass of solute to the volume of solution, expressed as a percent %(m/v)=m of solute (g) x100% v of solution (mL) % (Mass/Mass) -a ratio of mass of solute to mass of solution, expressed as a percent %(m/m)=m of solute (g) x100% m of solution (g) % (Volume/Volume) -a ratio of the volume of solute to the volume of solution, expressed as a percent %(v/v)= v of solute (mL) x100% v of solution (mL) ex.(m/v but applies to all % questions) g:msolute=17.5g msolvent=350mL r: %(m/v)= ? a: %(m/v)=msolute x100% msolvent m: =17.5g x100% 350mL =5.00% [3 sig digs] Very Small Concentrations of Solutions Parts per million (ppm) -a ratio of solute to solution x106 ppm=m of solute (g) x106 m of solution (g) Parts per billion (ppb) -a ratio of solute to solution x109 ppb=m of solute (g) x109 m of solution (g) ex.(ppm but same steps for ppb) g:mNaF=32.2mg=3.22x10-2g mH2O=20.0kg=2.00x104g r: ppm(m/m)= ? a: ppm(m/m)=mass of solute x106 mass of solution m: ppm(m/m)=3.22x10-2g x106 2.00x104g+3.22x10-2g =1.61ppm(m/m) Molar Concentrations -the amount in moles of solute dissolved in 1L of solution equation: C= n/V ex. Molar concentration g:c=0.154mol/L V=500mL=0.500L r:n=? m=? a:n=cV m:n=0.154mol/L(0.500L) =0.077mol m=Mn =(22.989770g/mol)(0.077mol) =1.77g ex. Molar concentration of ions g:n=0.212molFeCl3 V=0.175mL r:c=? a:c=n/v m:c=0.212molFeCl3/0.175mL =1.21mol/L Determining Solubility Effect of Ion Charge -compounds of ions with small charges tend to be soluble -compounds of ions with large charges tend to be insoluble -why? Increasing ion charge increases the attractive forces that hold the ions together Effect of Ion Size -the size of an atom is different than the size of its corresponding ion -in general, metallic ions tend to be smaller than their corresponding neutral atoms; non-metallic ions tend to be larger than their corresponding neutral atoms -small ions bond more closely