Chemical changes Flashcards
1
Q
What is electrolysis?
A
The decomposition (splitting) of an ionic aqueous solution using electrical energy to form new substances (elements).
2
Q
What is electrolysis used for?
A
- purification of metals (eg: copper, silver)
- can make new elements (eg: chlorine, hydrogen)
- cosmetics- removal of hair follicles
- glavanising (coating a metal with a protecting layer)
3
Q
What can copper be used for?
A
Electrical wiring and plumbing (but it has to be purified)
4
Q
List the reactivity series
A
Potassium Sodium Lithium Calcium Magnesium Aluminium Carbon Zinc Iron Tin Lead Hydrogen copper silver gold platinum
5
Q
How are elements above carbon extracted and how reactive are they?
A
Electrolysis. They are very reactive.
6
Q
How are elements below carbon but above hydrogen extracted and how reactive are they?
A
By carbon reduction. They are fairly reactive.
7
Q
How are elements below copper extracted and how reactive are they?
A
They are mined as they are found in their native state. They are unreactive.
8
Q
What are the disadvantages of electrolysis?
A
- uses lots of electrical energy (electricity)
- expensive
- environmentally unfriendly (burn fossil fuels to get energy)
- electrical energy (burning fossil fuels releases pollutant gases)
