C1 (1) Flashcards
What charge is given when an atom loses an electron in bonding?
Positive
What charge is given when an atom gains an electron in bonding?
Negative
What is an ion?
A charged atom
What are four additives that are added to foods and why?
Colouring = enhance appearance
Flavour enhancers = improve taste and smell
Anti?oxidants = preserve food
Emulsifiers = help oil and water to mix
What does an emulsifier have? (structure)
Hydrophobic tail (hates water, likes oil) Hydrophilic head (hates oil, likes water)
What happens when you shake oil and water together with an emulsifier?
Oil forms droplets surrounded by emulsifier with hydrophilic tail facing out. Other oil droplets are repelled but water attaches.
What are four reasons foods are cooked?
Better taste and texture
Easier to digest Eg. Potatoes
High temps kill microbes
Destroy poisons
What happens to eggs and meat when cooked?
Denature (change shape) because the energy breaks some of chemical bonds and the molecules take on a different shape
What happens when you heat baking powder?
Undergoes thermal decomposition
What is thermal decompoisiton?
When a substance breaks down into simpler substances when heated
What is the equation for baking powders thermical decomposition? (Sodium hydrogencarbonate)
Sodium hydrogencarbonate = sodium carbonate + carbon dioxide + water
2NaHCO(3) = Na(2) CO(3) + CO(2) + H(2)0
Why is baking powder used in baking?
CO(2) is released which makes cakes rise
What is esterification?
Heating a carboxylic acid with alcohol
An acid catalyst is usually used too
What is the esterification equation?
Acid + Alcohol = Ester + Water
What five properties to perfumes need and why?
Easily evaporates = to smell it
Non?toxic = won’t poison you
Unreactive with water = would react with sweat
Doesn’t irritate skin = could risk burning skin
Insoluble in water = so it doesn’t wash off
What are reasons for animal testing?
To check it won’t damage humans
What are reasons against animal testing?
Wrong to cause harm
Results might not be conclusive
Describe the following points in a solid
? Forces between particles
? Particle movement/shape
? Effect of heat
?Strong forces of attraction
?Don’t move (definite shape and volume)
? Vibrate more
Describe the following points in a liquid
? Forces between particles
? Particle movement/shape
? Effect of heat
?Some forces of attraction = free to move passed each other
?Don’t keep definite shape but keep same volume
? Move faster = liquid to expand
Describe the following points in a gas
? Forces between particles
? Particle movement/shape
? Effect of heat
?No force of attraction = free to move
?Don’t keep definite shape nor volume. Always fill any container
?Either expand or pressure increase
What is volatility?
How easy a liquid evaporates
What is evaporation?
When fast moving particles at surface overcome forces of attraction and escape
What is a solution?
A mix of a solute and solvent