C6 Flashcards
What can enzymes do as a detergent?
removes food and blood stains
How do detergents remove fat or oil stains from clothes?
- hydrophobic end bonds with grease
- detergent is bonded to water molecules
- hydrophobic tail lifts off grease
What chemical test shows fats are unsaturated?
add bromine water
-bromine water should lose its colour
How can washing soda soften water?
- hard water contains dissolved calcium ions and/or magnesium ions
- calcium ions and magnesium ions are removed from water
- calcium ions and magnesium ions removed by precipitation as insoluble carbonates
Hard water dont easily…..
what does it make instead?
form a lather with soap
-makes nasty scum instead
What does iron do when rusting?
loses 3 electrons to form Fe3+ - oxidised
What does oxygen do when rusting?
Each oxygen atom gains 2 electrons to become 02-
What happens during electrolysis?
- electric current is passed through an ionic compound causing it to decompose
- this creates a flow of charge through the electrolyte
- positive ions move to the cathode and gain electrons
- negative ions move to the anode and lose electrons
- As ions gain or lose electrons they are discharged from the solution at electrodes
advantages of hydrogen fuel cells?
- much more effecient than power stations
- fewer places for energy to be lost as heat
- no pollution
disadvantages of hydrogen fuel cells?
- producing the hydrogen requires alot of energy and this energy is gotten from fossil fuels
- hydrogen fuel cells often contain harmful catalysts which need to be disposed off - this costs money and takes time
how are hydrogen fuel cells used in space crafts?
- fuel cells are lightweight and compact dont take up much room
- no moving parts that could go wrong
- some of the products are used as drinking water
- no waster products
how are fuel cells trying to be used in car industry?
- no pollution as products are water and heat
- hydrogen can be obtained by decomposing water there is a large amount available
properties of CFC’s?
- non-toxic
- non-flammable
- insoluble in water
- low boiling points
What was the bad CFC which affected the ozone?
chloroflurocarbon
Equation for ozone
O3 + UV LIGHT —> O + O2
O2 + O —> O3
What does the ozone do?
absorbs UV light form the sun
Equations of breakdown of ozone with chlorine
- Cl + O3 → •ClO + O2
* ClO + O3 → •Cl + 2O3
CFC’S ……
breakdown to form chlorine atoms which affect the ozone
CFC’s only break up to form chlorine atoms when there is……
plenty of high energy ultraviolet light around
Hard water forms ….. which is a …..
Limescale and thermal insulator
Hard water contains
calcium ions and magnesium ions, as water flows through rocks which contains these ions, these ions dissolve in the water
How is rainwater slightly acidic?
CO2 from air dissolves in water to form carbonic acid
Equation for calcium hydrogencarbonate
carbon dioxide + water + calcium carbonate –> calcium hydrogencarbonate
What is temporary hardness?
hardness caused by hydrogen carbonate ion
