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
What is permanent hardness?
hardness caused by dissolved calcium sulfate
How is temporary hardness removed?
by boiling - hydrogen carbinate decomposes to form CaCO3
Experiment to compare hardness of water?
- add 100cmcubed of water to flask
- add 1cmcubed of soap solution in flask/put a bung in it and shake
- repeat it till good lather is formed(lasting lather is where bubbles stay on surface for at least 30 seconds
- record how much soap was needed
The equation for fermentation?(word and symbol)
glucose —>ethanol + carbon dioxide
C6H12O6 → 2 C2H5OH + 2 CO
What is important to prevent when trying to produce ethanol through fermentation?
prevent oxygen from getting to alcohol as it will convert ethanol into ethanoic acid
How else can ethanol be made and what are the conditions required?
Ethene + water —> ethanol
C2H4 + H2O → C2H5OH
-300 degrees and 70 atmospheres
-use phosphoric catalyst to speed up reaction
Compare fermentation with Ethene hyrdration?
- ferementation is a batch process so is slow and ineffecient/Hydration is continuous so is muc faster process
- ethanol made by fermentation is a renewable fuel so we wont run out
- Ethanol made by fermentation isnt very pure whilst ethanol made by hydration has a much higher purity
Name me an animal oil
Lard
Name me an plant oil
olive oil
Whats the difference between plant and animal oils
fats are solids and oils are liquids at room temp
What is meant by immiscible?
when oil dont mix with water
how can you create an emulsion?
mixing immiscible oil an water to form and emulsion by shaking to liquids vigourously
What emulsion is milk and what emulsion is butter?
milk-oil in water emulsion/less oil than water
butter-water in oil emulsion/more oil than water
how can unsaturated molecules be hydrogenated?
- vegetable oil are liquid at room temp
- hardened by reacting them with hydrogen in the presence of nickel catalyst at 60 degrees-HYDRATION
How can vegetable oils/animal oils affect health?
- vegetable oils are unsaturated/animal oils are saturated
- saturated fats less health than unsaturated fats(as saturated increase the cholesterol of blood)
- natural unsaturated oils reduce the amount of cholsterol
How does dry cleaning use solvents to remove any stains?
- weak intermolecular forces between solvent molecules
- when solvent is applied to clothes, intermolecular forces are formed between the solvent and the grease moleucles-grease molecules are surrounded by molecules of solvent
- When solvent is removed the grease molecule are removed with it
Elctrolysis equations
4OH- - 4e- —> O2 +2H2O at anode oxygen is made
2H+ + 2e- —> H2 at cathode hydrogen is made
