12.3 – 12.4   Student Notes

 

B.            Effects of Temperature and Pressure on Solubility

1.              Temperature Change

Most gases become

Most ionic solids become

Endothermic –                         à

Exothermic –                           à

2.              Pressure change

a.    Pressure tends to have

b.    LeChatelier’s Principle –

c.    All gases become

d.    Henry’s Law: Relating Pressure to the Solubility of a Gas in a Liquid

1.    Def –

       2.    S = kH P

              S –

              kH –

              P –

       3.    Applying Henry’s Law

In the chapter opening, we noted that 27 g of acetylene, C2H2, dissolves in 1 L of acetone at 1.0 atm pressure. If the partial pressure of acetylene is increased to 12 atm, what is its solubility in acetone?

 

II.   Colligative Properties

       A.   Def -

       B.   Ways of Expressing Concentration

              1.    Mass Percentage

 

              2.    Molality

 

3.              Mole Fraction

 

4.    Conversion of Concentration Units

       a.    Converting Molality to mole Fractions

An aqueous solution is 0.120 m glucose, C6H12O6. What are the mole fractions of each component in solution?

 

b.              Converting Molarity to Molality

An aqueous solution is 0.907 M Pb(NO3)2. What is the molality of lead nitrate, Pb(NO­3)2, in this solution? Then density of the solution is 1.252 g/mL.