Review Solutions: A ________________ ________________ of substances. Mixture - ___________________________. _____________ – uniform ______________ and properties. –Looks as if it’s one substance.

Solutions *** ___________ + Solvent =____________*** Solute – the substance being _____________. ( smaller / larger amount) _________ – the substance doing the dissolving. ( greater / lesser amount) –______________ = “universal solvent”

Solutions Link (SMART Notebook)

Eg. 1: NaCl in water (NaCl (aq) )  dissolves (therefore, it ( is / is not ) a solution) Solute = ______________ Solvent = ____________ Eg. 2: Sand in water  ( does / does not) dissolve (therefore, it is not a solution) Eg. 3: metal alloys (= metals mixed to form a solution): Zinc + Copper  Brass (therefore, it ( is / is not ) a solution)

Rules for Dissolving “Like ___________ Like” a.) Non-polar solvents dissolve _________________ solutes. (What is Non-polar??) Eg. Air (O 2 + N 2 +CO all are ( polar / non-polar ); therefore, is a solution) b.) ______________ solvents dissolve polar solutes. (What is Polar???) Eg. Water (H 2 O) + HF (drawing)

Rules for Dissolving c.) ____________ solvents dissolve ionic compounds (M+N-). (What is an Ionic compound???)

Examples for Dissolving ***Refer to Table F !!!*** Eg.1: NaCl(aq)  Na + (aq) + Cl - (aq) Salt dissolving in water 1 (pt. 2) Salt dissolving in water 1pt. 2 (drawing)

Examples for Dissolving (Cont’d) Eg.2: CaCl 2(aq)  Ca +2 (aq) + Cl - (aq) + Cl - (aq) (drawing) Eg.3: AgCl  ???

Concentration **Review: What is a solution made up of? Concentration: % of a solute in a solution There are 3 Types of Concentration calculations covered: 1.) Mass % 2.) ppm 3.) Molarity (M)

Concentration (Cont’d) 1.) Mass % = Q: What makes up a solution? Eg.What is the mass % of 10g of sucrose in 220g H 2 O?

Concentration (Cont’d) 2.) ppm (parts per million) = Eg.1: How many ppm are 10g of sucrose in 80g of H 2 O? Eg.2: A solution has a mass % of 6% O 2. How many ppm of O 2 are there?

Concentration (Cont’d) 3.) Molarity (M) = ** 1 L =______mLM = “molar” ** Remember Conversions of g  moles ; moles  g ** Eg.1:What is the Molarity of a solution that contains 2 mol of KCl in 4 liters of solution?

Concentration (Cont’d) Eg.2:What is the molarity of a solution that contains 30g of Sodium Hydroxide in 800ml of solution? Eg.3:Which has a greater concentration of salt (NaCl) – a 2M solution or a 4M solution? Explain. (Review Book, p.103, #’s  Homework!!!)

Standard Solutions Standard Solutions: Solution of _____________ _____________ Volumetric Flask – instrument used to make ______________________.

Eg.How would you make 1,000ml of a 2 molar NaCl (aq) ? Step 1: (calculate... moles  grams) How many grams of NaCl do you need to make 1,000ml of a 2M NaCl (aq) ?

Eg.How would you make 1,000ml of a 2 molar NaCl (aq) ? (cont’d) Steps 2-4: ( measure and combine ingredients) ** Salt (NaCl) goes into the flask First, and then water (H 2 O). ** (Step 2) Therefore, place ____g NaCl in 1,000ml _________________.

Eg.How would you make 1,000ml of a 2 molar NaCl (aq) ? (cont’d) (Step 3) Add a little _________________ to dissolve. (stir/mix) (Step 4) Then, fill (with _______) to the ______ml mark. (stir/mix again) End Result: ___M solution of NaCl ( = ___M NaCl (aq) ).

(** Remember... Water is the “__________ solvent”; therefore, assume ___________ is the solvent in solutions we work with, unless otherwise indicated! **) Eg.2: Describe (in Detail!) how you would make 100ml of a.5M KI (aq).

Diluting Solutions Concentrated – A solution with a lot of solute in a given amount of solvent. –Add more solute, or –Remove some solvent (evaporate, etc).

Diluting Solutions (Cont’d) Dilute – To make less concentrated (lower the concentration). –Add more solvent (water).

Diluting Solutions (Cont’d) Dilute solution – A solution with very little solute in a given amount of solvent. Eg.1:How many moles of KCl are in 1L of a 2M KCl solution? (drawing) Q.1: How can we dilute this solution to 1M? Q.2: If we had 4L, would the solution be more or less dilute?___________ What would the new molarity (M) be?

Diluting Solutions (Cont’d) If... **  and... ** # of moles stays the same (like in dilutions) ** then... ** M 1 V 1 = M 2 V 2  Equation for Dilutions ** M 1 = initial molarity V 1 = initial volume M 2 = final molarity V 2 = final volume

Diluting Solutions (Cont’d) ** M 1 V 1 = M 2 V 2 ** M 1 = initial molarity V 1 = initial volume M 2 = final molarity V 2 = final volume Eg.1:Calculate the concentration of the final solution when 20ml of a 6M HCl solution is diluted to 60ml.

Diluting Solutions (Cont’d) Eg.2: How much water must you add to 200ml of a 6M HCl solution to decrease its concentration to 2M? Eg.3: Review Book, p.107 #26-30.

Solubility Solubility: –The amount of solute that can be dissolved in a given amount of solvent at a particular temperature. *** Table G – Solubility Curves ***

Solubility Curves (Table G) Eg.NH 4 Cl – Solubility of NH 4 Cl in 100g of H 2 O (Table G)Table G Temperature ( ◦ C) Dissolved Solute Temperature ( ◦ C) Dissolved Solute

Solubility for... Gases: increase temp. = decrease solubility List the gases from Table G: Solids: increase temp. = increase solubility List the solids from Table G:

Solubility Questions (Table G) Q.1:What is most 40 ◦ C? A.) NaClB.) KClC.) KNO 3 D.) NaNO 3 Q.2: How many grams of KI could you dissolve in 50g of 10 ◦ C? Q.3: How many g of Potassium Nitrate can you dissolve in 400g of H 2 60 ◦ C? Q.4: Which of the following is the least soluble in 20 ◦ C? A.) NaNO 3 B.) KClC.) NaClD.) KI

Terms associated with Solubility: Saturated (“all desks in classroom taken”): A solution that contains the _____________ amount of ___________ it can a particular _________________.

Terms associated with Solubility: Unsaturated (“not all desks taken”): Solution that contains ( less / more ) than the maximum amount of _________ it can a given particular ____________.

Terms associated with Solubility: Supersaturated (“more students than desks available”): A solution that contains more than the maximum amount of solute it can a particular temperature. **This is often achieved by saturating a a high temp., and then cooling down the solution. Eg. Sodium thiosulfate (Demo. in class!)

Solubility *Diagram relating unsaturation, saturation, and supersaturation... **Graph out solubility curve (from Table G) of NH 4 Cl.** Label: unsaturated, saturated, and supersaturated.

Solubility Questions Q.1:SO 10 ◦ C a.) When is it unsaturated? b.) When is it saturated? c.) When is it supersaturated? Q.2:45g KNO 3 in 100g H 2 30 ◦ C? A.) Unsaturated B.) Saturated C.) Supersaturated Q.3:80g NH 4 Cl in 100g H 2 90 ◦ C? A.) UnsaturatedB.) SaturatedC.) Supersaturated Q.4:___ g of KCl is needed to saturate 200g H 2 50 ◦ C?

Solubility is affected by... 1.) Temperature A.) Solids:increase Temp.  increase solubility (Direct) B.) Gases:increase Temp.  decrease solubility (Indirect) 2.) Pressure (Gases only!) A.) Gases:increase Pressure  increase solubility (Direct) Q.: How do you keep CO 2 in Coca-Cola???

Effect of Solutes on physical properties of Solvents: A.) Boiling pt. (b.p.) Elevation Water (a solvent!) is more attracted to dissolved particles (solute, such as NaCl)  more IMF  more energy needed to boil  higher b.p.! (diagram) Eg.Water b.p. = 100 ◦ CNaCl(aq) b.p = 105 ◦ C

Effect of Solutes on physical properties of Solvents: B.) Freezing pt. (f.p.) Depression Solute (such as NaCl) added to Solvent (such as water) lowers freezing pt.! Eg.Water f.p. = 0 ◦ CNaCl (aq) f.p. = -15 ◦ C

2 Factors which affect b.p. elevation and f.p. depression... 1.) Concentration: a.) b.p. increase concentration  increase b.p. b.) f.p. increase concentration  decrease f.p. Eg. Which of the following will produce the lowest f.p.? A.) 1M C 6 H 12 O 6 C.) 4M C 6 H 12 O 6 B.) 2M C 6 H 12 O 6 D.) 3M C 6 H 12 O 6

2 Factors which affect b.p. elevation and f.p. depression... 2.) # of particles produced in solution: a.) b.p. increase # of particles  increase b.p. b.) f.p. increase # of particles  decrease b.p. Eg. Which of the following 2M solutions has the highest b.p.? A.) C 6 H 12 O 6 D.) (NH 4 ) 3 PO 4 B.) NaClE.) C 2 H 5 OH C.) CaCl 2 F.) NH 3