Question 4

pH VERSUS VOLUME ADDED 12 0.0 20.0 40.0 60.0 80.0 100. Volume 0.100
 MNaOH Added (mL)

  • Equivalence occurs at 40.0 ml titrant added. So half equivalence at 20.0 ml of titrant.

  • At half equivalence, [HA]=[A-]. Below half equivalence, more acid species present.

    14 12 10 pKa2=7.19 8 6 4 2 pKa1 - 1.85 Titration of 40.00 mL of
0.1000 M H2S03 with 0.1000 MNaOH PH 9.86 at second equivalence (HSOÜ)
= S032- legion pH 4.25 at first equivalence point tH2S03) HSOÜI
Buffer regioC, 20 40 60 point 80 Volume of NaOH added (

Question 8

Kinetic Temperature The expression for gas pressure developed from
 kinetic theory relates pressure and volume to the average molecular
 kinetic energy. Comparison with the ideal gas law leads to an
 expression for sometimes referred to as the kinetic temperature. = —N
 —mv2 PV = nRT This leads to the expression 1 2 — mv 2 21 3k 1 2 2
 where N is the number of molecules, n the number of moles, R the gas
 constant, and k the Boltzmann constant. The more familiar form
 expresses the average molecular kinetic energy: 1<Eavg 2 3 2 Show

Question 19

Reactions can be 'driven by enthalpy' (where a very exothermic
 reaction (negative AH) overcomes a decrease in entropy) or 'driven by
 entropy' where an endothermic reaction occurs because of a highly
 positive AS. Example 1: The formation of NaCl(s) from its elements is
 spontaneous and releases a great deal of heat. Gibbs Free Energy -

Question 26

Zero order 1st order 2nd Order (b) Plots from integrated rate
 equations: Zero order Conc. 1st order Conc. 2nd order (Conc.)2 3rd
 order 3rd order (Conc.)

Question 25

  • Larger ionic radius --> smaller lattice energy --> lower boiling point

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