U2 AOS2 Chapter 14

Question 1

global warming

Answer 1

a long term increase in the average global temperature of Earth’s climate due to human activities

Question 2

greenhouse effect

Answer 2

the natural warming of the earth that results when gases in the atmosphere trap heat from the sun that would otherwise escape into space; necessary for life on earth

Question 3

greenhouse gases

Answer 3

molecules that absorb and re-emit infrared radiation from the sun

Question 4

ideal gas

Answer 4

substance assumed to be composed of molecules of negligible volume w/ no intermolecular reactions

Question 5

infrared radiation

Answer 5

heat energy emitted from the sun

Question 6

pressure

Answer 6

force a gas exerts on the walls of its container

Question 7

standard laboratory conditions (SLC)

Answer 7

conditions used as a standard for experiments (298K and 100kPa)

Question 8

potent greenhouse gases

Answer 8

CO2, methane (CH4), H2O, O3

Question 9

what happens to greenhouse gases when they are exposed to infrared radiation? (scientific explanation)

Answer 9

infrared radiation hits molecule, bonds vibrate and bend at greater rate, molecule re-emits heat energy in all directions (some escapes, most traps in lower atmosphere) = heats up earth

Question 10

how do greenhouse emissions create climate change?

Answer 10

heat trapped, surface temp rises, climate change

Question 11

causes of greenhouse gas emissions

Answer 11

agriculture, forestry, industry, energy supply, waste and waste water, transportation, buildings, electricity supply, heat supply, livestock

Question 12

ideal gases characteristics

Answer 12

experience no IMFs, have zero volume individually, exchange no energy when a collision occurs

Question 13

characteristics of gases

Answer 13

has no fixed shape or volume, can expand or contract to fill available volume

Question 14

what is pressure (scientific explanation)

Answer 14

molecules in a gas constantly moving, colliding w/ walls and other molecules - force of collisions = pressure

Question 15

Units of pressure

Answer 15

Pa, kPa, atm

Question 16

universal gas law w/ fixed volume

Answer 16

increasing temp and increasing mol = increasing pressure eg. gas cylinder

Question 17

universal gas law w/out fixed volume

Answer 17

increasing temp and increasing mol = increasing volume

Question 18

C to K

Answer 18

+ 273

Question 19

Pa to kPa

Answer 19

/1000

Question 20

atm to kPa

Answer 20

/0.987 x100kPa

Question 21

universal gas constant

Answer 21

8.31 J mol-1 K-1

Question 22

ideal gas constant (SLC)

Answer 22

24.8L mol-1

Question 23

molar volume

Answer 23

n = V/Vm or M=m x RT/pV

Question 24

advantages and disadvantages of using gravimetric analysis and electrical conductivity testing

Answer 24

grav:
- advantage: requires fewer materials (only an analyte and a means of drying and weighing)
- disadvantage: possibility of incorrectly weighing, reaction may be slow.
elec:
- Advantage: quick and easy, equipment is portable
- disadvantage: cannot be used to determine the concentration of a particular element, instead providing an indication of the overall ionic content of a sample

Question 25

accuracy

Answer 25

the closeness of measurements to the true value

Question 26

precision

Answer 26

the closeness of measurements to each other