SolutionSolution

A solution is a homogenious mixture of a A solution is a homogenious mixture of a substance mixed in a second substance.substance mixed in a second substance.

An alloy is a solution of metals evenly An alloy is a solution of metals evenly mixed together, an example is Brassmixed together, an example is Brass

Air is a soltution of evenly mixed gassesAir is a soltution of evenly mixed gasses

We will be dealing primarily with We will be dealing primarily with liqued solutions.liqued solutions.

Terms: The solute is the thing that is Terms: The solute is the thing that is being dissolvedbeing dissolved

The solvent is the thing doing the The solvent is the thing doing the dissolvingdissolving

ExamplesExamples

If salt is added to waterIf salt is added to water

The salt is the soluteThe salt is the solute

The water is the solventThe water is the solvent

solubilitysolubility

Different things have different Different things have different solubilitysolubility

Sugar & salt dissolves (Soluble)Sugar & salt dissolves (Soluble)

The metal spoon & oil dont The metal spoon & oil dont (insoluble)(insoluble)

Why do things dissolveWhy do things dissolve

If a molecule is polar or ionic (has a If a molecule is polar or ionic (has a charge) it will be attracted to the charge) it will be attracted to the charges in water.charges in water.

The charges of the water will ‘latch The charges of the water will ‘latch onto’ the charges of the solute and onto’ the charges of the solute and dissolve itdissolve it

Why do things not dissolveWhy do things not dissolve

If something has no charge (non If something has no charge (non polar) it wont be attracted to the polar) it wont be attracted to the water.water.

This will make is insoluble.This will make is insoluble.

FatsFats

Oil, fats, grease etc. are all non polar, Oil, fats, grease etc. are all non polar, they have no charges for the water they have no charges for the water to ‘latch onto’ to dissolve themto ‘latch onto’ to dissolve them

Soap has 2 sides, 1 polar 1 not polar.Soap has 2 sides, 1 polar 1 not polar.

The non polar side can dissolve the The non polar side can dissolve the grease, and the polar side can grease, and the polar side can dissolve in water. dissolve in water.

Factors that affect solubilityFactors that affect solubility

Think about a warm soda…Think about a warm soda…

What happens to the solubility of What happens to the solubility of gasses in warm and cold water?gasses in warm and cold water?

What happens to the solubility of What happens to the solubility of sugar in hot or cold water? sugar in hot or cold water?

TemperatureTemperature

As temperature increases more solid As temperature increases more solid can be dissolved.can be dissolved.

As temperature increases less gas As temperature increases less gas can be dissolved.can be dissolved.

PressurePressure

When you open up a bottle of soda When you open up a bottle of soda the CO2 gas rushes out…the CO2 gas rushes out…

What does this tell us about the What does this tell us about the effect of pressure on the solubility of effect of pressure on the solubility of gas? gas?

Pressure Pressure

As pressure decreases the solubility As pressure decreases the solubility of gasses decrease.of gasses decrease.

This is why as the bottle is open (and This is why as the bottle is open (and pressure goes down) gas rushes out pressure goes down) gas rushes out of the soda.of the soda.

But it tastes just as sweet. Pressure But it tastes just as sweet. Pressure doesn’t affect solubility of solids doesn’t affect solubility of solids

Table GTable G

Table G on your reference table tells Table G on your reference table tells you the solubility of various you the solubility of various compounds in different temperature compounds in different temperature water.water.

ConcentrationConcentration

If we dissolve a lot of sugar in water If we dissolve a lot of sugar in water we may say its concentrated.we may say its concentrated.

Or if we dissolve a little sugar we Or if we dissolve a little sugar we may say its dilute.may say its dilute.

But these terms are imprecise But these terms are imprecise

MolarityMolarity

Molarity is how we measure the Molarity is how we measure the concentration of a solution.concentration of a solution.

It means moles of solute (sugar) per It means moles of solute (sugar) per liter of solvent (water)liter of solvent (water)

Molarity = moles solute/liters solventMolarity = moles solute/liters solvent

ExampleExample

What is the molarity of a solution What is the molarity of a solution that has 4 moles of NaOH in .5L of that has 4 moles of NaOH in .5L of solution?solution?

What is the molarity of a solution What is the molarity of a solution that has 12 moles of HCl in 6 liters of that has 12 moles of HCl in 6 liters of solution?solution?

ExampleExample

A can of soda has .21 moles of sugar A can of soda has .21 moles of sugar in .35 Litersin .35 Liters

A carton of apple juice has .07 moles A carton of apple juice has .07 moles of sugar in .12 Litersof sugar in .12 Liters

Find the molarity for eachFind the molarity for each

What is molarity of a solution that What is molarity of a solution that has 82.0 grams of Ca(NOhas 82.0 grams of Ca(NO33))22 in 2 liters in 2 liters

Parts per millionParts per million

Molarity measures the concentration Molarity measures the concentration of a solute when there is a lot of it.of a solute when there is a lot of it.

But what it we have a tiny amount of But what it we have a tiny amount of a solute.a solute.

Parts per millionParts per million

PPM (parts per million) is used to PPM (parts per million) is used to measure the concentration of tiny measure the concentration of tiny amounts.amounts.

For instance a pool has 2 grams of For instance a pool has 2 grams of chlorine per 1,000,000 grams of chlorine per 1,000,000 grams of waterwater

PPMPPM

The formula for PPM is found on the The formula for PPM is found on the refernece tablerefernece table

Ppm = grams solute/ grams solutionPpm = grams solute/ grams solution

then times 1,000,000then times 1,000,000

ExampleExample

If .0972 grams of carbon dioxide can If .0972 grams of carbon dioxide can be dissolved in 100 grams of water be dissolved in 100 grams of water what is the ppm concentration?what is the ppm concentration?

PrecipitatesPrecipitates

When 2 liquids are reacted they can When 2 liquids are reacted they can sometimes react to form a solid that sometimes react to form a solid that is un-dissolvable.is un-dissolvable.

This solid is called a precipitate. This solid is called a precipitate.

Table FTable F

Table F Lists chemicals that can be Table F Lists chemicals that can be dissolved, or form precipitates.dissolved, or form precipitates.

Example Example

does Lidoes Li33(PO(PO44) dissolve in water?) dissolve in water?

What about Al(POWhat about Al(PO44))

Colligative propertiesColligative properties

When a substance is dissolved in When a substance is dissolved in water, it spreads the water water, it spreads the water molecules out further.molecules out further.

This makes it harder for them to This makes it harder for them to clump together and lowers the clump together and lowers the freezing point.freezing point.

If something is dissolved in water you If something is dissolved in water you also need to break to connections also need to break to connections between the solute and water before between the solute and water before it can evaporate.it can evaporate.

So a solute raises the boiling pointSo a solute raises the boiling point

RecapRecapAdding a solute to a solution Adding a solute to a solution

Lowers the freezing pointLowers the freezing point

Raises the boiling pointRaises the boiling point

The more solute you add the greater The more solute you add the greater the effect the effect

Vapor pressureVapor pressure

Even though a substance is in the Even though a substance is in the liquid phase some molecules have liquid phase some molecules have enough energy to escape their enough energy to escape their neighboring molecules and enter the neighboring molecules and enter the gas phase.gas phase.

Vapor pressureVapor pressure

These gas particles exert preasure These gas particles exert preasure on the air around them,on the air around them,

As the temperature goes up, more As the temperature goes up, more molecules evaporate and the vapor molecules evaporate and the vapor pressure increasespressure increases

Table HTable H

Table H, tells us the vapor pressure Table H, tells us the vapor pressure that a chemical exerts as the that a chemical exerts as the temperature is changedtemperature is changed

When the vapor pressure of a When the vapor pressure of a substance reaches the same substance reaches the same pressure of the surrounding air it will pressure of the surrounding air it will boil (turn to gas). boil (turn to gas).

Vapor PressureVapor Pressure

Something boils when its vapor Something boils when its vapor pressure equals the surrounding air pressure equals the surrounding air pressurepressure

SO If the pressure of the surrounding SO If the pressure of the surrounding air changes then the boiling point will air changes then the boiling point will changechange