chem

Question 1

The Chemical basis for the design, construction and operation of treatment processes depend on fundamental these properties:

Answer 1

• Air pollution
• Water pollution
• Air quality management
• Water quality management
• Solid waste management
• Climate change
• Sustainability

Question 2

A system is in equilibrium when

Answer 2

• It does not vary with time (steady state)
• It is well mixed
• There is no net flow of mass, heat or species
• The net rate of chemical reaction is zero

Question 3

What is pH by definition and what does it do?

Answer 3

negative the log of the hydrogen ion activity
pH = -log [H+]
pH affects solubility of metals, corrosiveness of water, other chemical reaction rates

Question 4

what range of pH values are corrosive?

Answer 4

acids from pH 0 to 3 and bases from pH 11 to 14

Question 5

acids produce ___ in solution and bases produce ___ in solution

Answer 5

acids –> H
base –> OH

Question 6

what are the strong acids mentioned in class?

Answer 6

HCl, HNO3, H2SO4, HBr, HI, HClO4

Question 7

what are the weak acids mentioned in class?

Answer 7

acids like HCN, HF, H2S, HCOOH, i.e.

all acids besides HCl, HNO3, H2SO4, HBr, HI, HClO4

Question 8

what happens to Kw and Ph as temperature increases?

Answer 8

Kw increases and Ph decreases

Question 9

how does the concentration of a soluble gas ([gas]aq) change as temperature increases?

Answer 9

as temp increases the solubility of [gas]aq decreases

Question 10

what is alkalinity?

Answer 10

a measure of a water’s capacity to neutralize acids

Question 11

what are the contributors of alkalinity in most waters?

Answer 11

[HCO3-] = bicarbonate
[CO3 2-] = carbonate
[OH-] = hydroxide

Question 12

what are five properties of organic compounds?

Answer 12

1. organics all have the CARBON atom as the main structural component
2. organics are usually combustible
3. organics are usually less soluble in water than inorganics
4. several organics have the same formula but different properties (isomers)
5. most organics can serve as a source of food for bacteria and other organisms

Question 13

what are the three major classifications of organic compounds?

Answer 13

1. aliphatic
2. aromatic
3. heterocyclic

Question 14

what are the three types of aliphatic hydrocarbons?

Answer 14

straight chain - hexane

branched - iso-hexane

cyclic - cyclohexane

Question 15

what are the characteristics of saturated compounds?

Answer 15

-no double bonds
-each carbon atom is attached to four other atoms
-the molecule is saturated with respect to bonds

Question 16

what are the characteristics of unsaturated compounds?

Answer 16

-double or triple bonds
-the molecule contains two or more carbons that are joined by double or triple bonds

Question 17

what is adsorption?

Answer 17

the amount of contaminant sorbed onto particles (soils, sediments) is proportional to the amount dissolved in water

adsorption is the physical and or chemical process in which a substance accumulates at a solid-liquid interface