16. Applications of Aqueous Equilibria Flashcards
(15 cards)
Any form of precipitation with acidic components (rain, snow, fog, hail, dust) - ph<7
Acid rain
Causes of acid rain (2 pt)
- Burning oil, gas, and coal in power stations (SO2)
- Burning oil and gas in motor vehicles (NOx)
Problems caused by acid rains (4 pt)
- Increases acidity of rivers, lakes, seas, kill aquatic life
- Increases acidity levels of soils, kill vegetation
- Destroy roots and leaves of forests
- Erode buildings and monuments (esp. limestone)
Solution that lessens the change in pH after the addition of a strong acid or base - usually consists of a conjugate acid-base pair
Acid-base buffer
The effect on an equilibrium involving a substance that adds an ion that is a part of the equilibrium (this is how a buffer works)
Common-ion effect
Buffer components (HA and A-) consume small amounts of added OH- or H3O+ by a shift in equilibrium position
How a buffer works
Decrease in blood pH
Acidosis
Increase in blood pH
Alkalosis
Buffer system in blood
Bicarbonate buffer and phosphate buffer
Measure of the ‘strength’ of the buffer, its ability to maintain the pH following the addition of strong acid or base
Buffer capacity
pH range over which the buffer is effective - related to the ratio of buffer component concentrations
Buffer range
How to make a buffer
- Select weak acid with similar pKa to desired pH, determine its conj. base
- Calculate ratio of buffer component conc
- Determine buffer conc, calculate required vol of stock solutions and/or masses of components
- Mix solution
- Check pH and adjust to desired pH
Weak organic acid whose colour differs from that of its conjugate base
Acid-base indicator
Number of moles of OH- added = number of moles of H3O+ originally present
Equivalence point
Indicator changes colour
End point
