5.3: Reactions and Environmental Issues

Question 1

in/complete combustion

Answer 1

complete:
hydrocarbon + O2 -> H2O + CO2

incomplete:
hydrocarbon + O2 -> H2O + CO2 + CO

Question 2

nitrogen oxides

Answer 2

the high temperatures present in a car engine allow nitrogen gas to react with oxygen to produce nitrogen oxides. These compounds contribute to smog and ground level ozone.

Question 3

catalytic converters

Answer 3

put them on the exhaust pipe of your car, the precious metals coated on act as catalysts, and speed up the decomposition of the nitrogen oxides into N2 and O2

Question 4

recovering gold using cyanide and zinc

Answer 4

rock that contains gold ore is crushed into a fine powder and placed into heaps. sprayed with a sodium cyanide solution. The soluble cmpd containing gold is drained away from the ore (leaching).
to recover gold from the solution: react with zinc. the zinc displaces the gold.

there are better, less harmful methods, but this is the most cost-effective

Question 5

cleaning and disinfecting pools

Answer 5

chemicals are used to stop bacterial growth

different types of chlorinating agents are not compatible with each other. can be explosive, corrosive, etc.

Question 6

HHPS

Answer 6

Hazardous Household Products System
explosive
corrosive
flammable
poison

Question 7

bleach and ammonia

Answer 7

produces chlorine gas or chloramines, all are toxic