Transcript Chapter 3_section 3.7

3.6 Solubility
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Solution: homogeneous
mixture or mixture in which
components are uniformly
intermingled
Solute: substance that is
being dissolved in solvent
Solvent: substance that
dissolves solvent and present
in a large amount
Aqueous solutions:
solutions with water as the
solvent
Solubility
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Saturated: A solution in which the maximum amount
of solvent has been dissolved. Any more solute added
will sit as crystals on the bottom of the container
Unsaturated: A solution in which more of solute can
be dissolved
Concentrated: a relative large amount of solute is
being dissolved in solvent
Diluted: a relative small amount of solute is being
dissolved in solvent
Solution_Molarity
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Molarity: the number moles of solute per volume of
solution in liters
moles of solute
Molarity = -----------------------Liters of solution
unit = mol/L or M (molar)
Standard solution: is a solution whose concentration
is accurately known.
Example
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What is the molarity of solution made by
dissolving 2.355g of H2SO4 in water and dilutin
to a final volume of 50.0mL
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Calculate the molarity of a solution prepared by
dissolving 11.5 g of solid NaOH in enough
water to make 1.50 L of solution
Calculating volume and mass
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Determine how much volume (in ml) will be
needed to dissolved 2.50 g of solid NaCl to
make 0.050M solution.
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How many grams of solute would you use to
prepare 1.50L of 0.250 M glucose (C6H12O6)
3.8 Dilution
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Reducing the original
concentration of a
chemical solution
A process of transferring
solution to achieve a the
desired molarity by
diluting with solvent
Moles of solute after dilution =
moles of solute before dilution
Formula  M1 V1 = M2 V2
Example
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What volume of 16 M sulfuric acid must be used to
prepare 1.5L of 0.10 M of H2SO4 solution?
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What is the final concentration if 75.0 mL of a 3.50M
glucose solution is dilute to a volume of 400.0mL?
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Calculate the new molarity if a dilution is made for:
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25.0 ml of water is added to 10.0 mL of 0.251 M CaCl2
Examples
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Stomach acid, a dilute solution of HCl in water,
can be neutralized by reaction with sodium
hydrogen carbonate, NaHCO3 NaHCO3,
according to the equation
HCl(aq) + NaHCO3(aq)  NaCl(aq) + H2O(l) + CO2(g)
How many milliliters of 0.125M NaHCO3 solution
are needed to neutralized with 18.0mL of
0.100M HCl?
Examples
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A 25.0mL sample of oxalic acid is titrated and
found to react with 94.7 mL of 0.200M NaOH.
What is the molarity of the oxalic acid solution?
The reaction is
2NaOH(aq) + H2C2O4(aq)  C2O4Na2(aq) + 2H2O(l)
Calculating the mass
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When aqueous solutions of Na2SO4 and
Pb(NO3)2 are mixed, PbSO4 precipitates.
Calculate the mass of PbSO4 formed when 1.25 L
of 0.0500 M Pb(NO3)2 and 2.00 L of 0.0250 M
Na2SO4 are mixed
Na2SO4(aq) + Pb(NO3)2(aq)  PbSO4(s) + 2NaNO3(aq)
Example
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What volume of 0.101 M HNO3 is required to
neutralize with 24.9 ml of 0.00491 M
Ba(OH)2(aq)?