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8.1 Solutions

Mixture = 2 or more components

Solute= substance in the lesser amount

Solvent= substance in the greater amount

Solution = homogeneous mixture

Water is a very common solvent.Latin for water is aqua, therefore called aqueous solutions, and symbolized by (aq).

Table salt

NaCl (s)

Table salt dissolved in water

NaCl (aq)

Water will dissolve any substance that is “like” water, in other words, polar.We will look at ionic compounds as “extreme” polar.

Polar solvents dissolve polar solutes Nonpolar solvents dissolve nonpolar solutes Like dissolves

like

hydrogen bondingN, O, F of one -------------- H of

another

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NaCl Ionic “extreme polar”Yes dissolves in waterNo in nonpolar solvents

Sugar Molecular PolarYes dissolves in waterNo in nonpolar solvents

Oil Molecular NonpolarNo does not dissolve in waterYes dissolves in nonpolar solvents

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Chemical equationsionic solutes

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Chemical equationsmolecular solutes

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some particles break-up as they dissolve, others do not.

Electrolytes

Strongelectrolyte

nonelectrolytetotal break-up partial break-up No break-up

weakelectrolyte

electrolytes conduct electricity.

A substance that produces ions in solution can conduct electricity.

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Strong electrolytesdissolve with complete ionization

Weak electrolytesdissolve with partial ionization

Nonelectrolytesdissolve with no ionization

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Solution = mixing of particles (homogeneous)mixing = ability to interact

ability to interact = chemical nature of particles

Very soluble insolublesolubleSlightlysoluble

When an insoluble substance forms during a reaction , we call it a precipitate

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There are several types of kidney stones based on the type of crystals of which they consist. The majority are calcium oxalate stones, followed by calcium phosphate stones.

Barium sulfate enhanced X-ray of the abdomen shows the large intestine

Kidney stone

Kidney stones result when urine becomes too concentrated and substances in the urine crystalize to form stones. Symptoms arise when the stones begin to move down the ureter causing intense pain. Kidney stones may form in the pelvis or calyces of the kidney or in the ureter.

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Any amount pass this limit does not dissolve.

Solubility = maximum value

Solubility is T dependent.

Solubility = the amount of solute that can be dissolved in 100 mL of H2O

At 20 ˚CNaNO3 84gKNO3 45g

To quantify the degree of mixing, we use solubility

Net ionic equations

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Concentration = ratio amount of soluteamount of solvent

mass/mass % % = g solute x 100 g solution

mass/volume % % = g solute x 100ml solution

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M = molesL soln.

moles = grams MM

Molarity and Dilution

M = grams MM L soln.

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Dilute add solvent lower concentration

C1V1 = C2V2

C = % or M

let 1= conc. 2 = dilute

n1 = n2

M = n Ln = M x L = C V

In osmosis, water flows through a semipermeable membrane from the lower concentration into the higher concentration.

highlow

The body is mostly water.Water is the solvent for all living matter.

Do not confuse with diffusion, where solute particles

such as Cl- move from high to low concentration.18

The level of the solution with the higher concentration rises.The concentrations of the two solutions become equal with time.

Water is the only molecule that moves freely between cells and the extracellular fluid. This provides the extracellular and intracellular compartments with a state of osmotic equilibrium in which the total amount of solute per volume of fluid is equal on both sides of the cell membrane.

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The liquid level in the tube rises until equilibrium is reached (concentrations are the same)

The pressure needed to prevent osmosis is called Osmotic pressure .

A hypotonic solution • Has a lower osmotic pressure than red blood cells.• Has a lower concentration than physiological

solutions. • Causes water to flow into red blood cells.• Causes hemolysis: RBCs swell and may burst.

A hypertonic solution• Has a higher osmotic pressure than RBCs.• Has a higher concentration than physiological solutions. • Causes water to flow out of RBCs.• Causes crenation: RBCs shrinks in size.

An isotonic solution• Is known as a “physiological solution”.• Exerts the same osmotic pressure as red blood

cells. • 5.0% glucose or 0.90% NaCl is used medically

because each has a solute concentration equal to the osmotic pressure equal to red blood cells.

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