chemicals in our lives

Question 1

what are the risks of eating salts in food?

3 answers

Answer 1

• high blood pressure
• heart failure
• strokes

Question 2

what are salts used for in foods?

2 answers

Answer 2

• flavouring

- preservative

Question 3

what are the uses of alkalis?

4 answers

Answer 3

• neutralising acidic soils
• making soap
• making glass
• dying cloth

Question 4

what are the stories in magnetism?

Answer 4

• as volcanic lava solidifies, igneous rocks form
• magnetic materials line up along the magnetic field + mf changes over time
• can date rocks and track slow movement of cont using changes in magnetic patterns, linked 2 radioactive decay
• support plate tectonic theory

Question 5

are chemicals safe?

Answer 5

may accumulate in food chains, ending up in human tissues

Question 6

should we worry about PVC?

Answer 6

plastic containing hydrogen, chlorine and carbon

plasticiser mol leach out of PVC and harm animals and give long term effects on fish

if PVC burnt, dioxin produced, build in fat and have cancer

Question 7

what are the benefits and risks to drinking water?

Answer 7

chlorine added to kill micro eg water borne micro which cause disease like typhoid

• chlorine = toxic gas, danger if too much present
• chlorine can react with organic mat forming toxic compounds DPS

Question 8

whats the electrolysis of brine?

Answer 8

• makes chlorine + hydrogen gas + sodium hydroxide solution
• anode positive electrode (chlorine forms)
• cathode negative electrode (hydrogen forms)

expensive

Question 9

whats the environmental impact on the products of electrolysis?

Answer 9

• plastics by chlorine are non biodegradable
• mercury diaphragm releases waste, enters food chain
• chlorine in paper bleaching releases dioxins increasing cancer

Question 10

how to manufacture alkalis?

Answer 10

leblanc process

made sodium carbonate by salt and limestone with coal

gave off hydrogen chloride and produced waste that released hydrogen sulfide

Question 11

why is rock salt spread on icy roads?

Answer 11

• salt gives grip
• shows up so people know its gritted
• salt lowers freezing point preventing ice to form easily

Question 12

how can extracting salt affect the environment?

Answer 12

• ground subsiding

- salt waste affect plants and animal by drying them up through osmosis

Question 13

how can salt be extracted?

Answer 13

• mining rock salt

- collecting and evaporating sea water