Module 2: Water, pH, Solutions

Question 1

Solvent

Answer 1

substance that dissolves solute resulting in a solution

Question 2

Homogenous Mixture

Answer 2

composed of 2/more substances

Question 3

Acid vs Base

Answer 3

proton donor

proton acceptors

Question 4

Strong acid

Answer 4

dissociate into proton and weak conjugate base

higher tendency to lose its proton

Question 5

K>1

Answer 5

equilibrium favours products

Question 6

K<1

Answer 6

equilibrium favours reactants

Question 7

Larger the Ka…

Answer 7

stronger the acid

smaller the pKa

Question 8

Titration

Answer 8

slow addition of one solution of known conc. (titrant) to known volume of another solution of known conc. (analyte) until rxn neutralizes (shown by colour change)

Question 9

Titration curve

formic acid

Answer 9

1. pH of formic acid =1.9
2. Ratio and pH increase as more NaOH added
3. Midpoint: [HCOO-]=[HCOOH]
   pH=pKa=3.75

Question 10

Buffer solution

Answer 10

solution that resists changes in pH

Question 11

Buffering region

Answer 11

1 pH unit on either side of midpoint pH

Question 12

Phosphate vs Bicarbonate buffer system

Answer 12

effective b/w pH 5.9-7.9 (Max effective at close to 6.86)

effective near pH 7.4

Question 13

Acidosis

Answer 13

pH of blood below normal (7.4)
ex: diabetes
headaches, nausea, vomitting, diarrhea

Question 14

Alkalosis

Answer 14

pH of blood higher than normal (7.4)

ex: hyperventilating: rapid breathing elicited by stress/anxiety -leads to dizziness, headaches, weakness, fainting

Question 15

Second Law of Thermodynamics

Answer 15

any spontaneous process increases disorder of the universe

positive entropy=increase in disorder (more moles of product)

Question 16

Gibbs free energy

& trends

Answer 16

amount of energy in system available to do useful work

-delta G=spontaneous
+delta G=non-spontaneous
delta G=equilibrium

deltaH > TdeltaS =enthalphy-driven
deltaH < TdeltaS =entropy-driven