Show:
Definitions
Water
Heat & Energy
Acids & Bases
Leavening agents
100
The amount of heat required to raise the temperature of one gram of water 1 degree Celsius
Calorie
100
An ice cube is melting. Does the temperature of the water change while the ice cube is melting?
No.
100
What direction does heat flow?
From a hot body to a cold body
100
Name 3 properties of an acid
1. Tastes sour 2. Turns litmus paper from blue to red 3. pH is less than 7 4. Reacts with a base to produce carbon dioxide 5. Feels like water on skin
100
Give 3 examples of how air is incorporated into foodstuffs
1. Mixing 2. Creaming 3. Sifting 4. Beating 5. Whipping
200
The name given to the type of material that does not transmit heat or electrical energy
Insulator
200
What happens to the density of water when it freezes?
It decreases
200
A form of energy associated with the random motion of molecules, which will raise the temperature of a body to which it is added
Thermal energy
200
Name 3 properties of a base
1. Tastes bitter 2. Turns litmus paper from red to blue 3. Feels soapy on the skin 4. pH is greater than 7 5. Reacts with acids to produce carbon dioxide
200
What happens to the carbon dioxide gas produced by yeast at high temperatures?
Yeast dies at 140 deg and carbon dioxide production stops.
300
A chemical reaction or physical change in which heat is absorbed
Endothermic
300
What happens to the volume of water when it freezes?
It increases.
300
Is the process of water freezing an endothermic or exothermic process?
Exothermic because the energy in the water is being released.
300
Give one example of a basic salt
NaHCO3 (Sodium bicarbonate a/k/a baking soda)
300
When using steam as a leavening agent, why should you place the food item in a preheated oven?
Because the moisture in the food item must vaporize to create steam. If the oven is cool when the food is placed inside, the moisture will heat up slowly and will simply evaporate and leavening will not occur.
400
A material that provides protons or increases the concentration of the hydronium ion in solution
Acid
400
Does water boil at 212 deg F at all elevations above sea level? Explain
No. As the atmospheric pressure decreases (at higher elevations) the boiling point decreases and vice-versa
400
Name 3 things that affect the rate of heat transfer?
1. Difference in temperature between the 2 objects 2. Conductivity of the material 3. Thickness or distance that the heat has to be conducted 4. Amount of contact between the 2 objects 5. Specific heat of each object involved
400
Give one example of an acidic salt
Cream of tartar is the most common acidic salt in the kitchen
400
Explain the acid/base reaction
The base in a food item (baking soda) reacts very quickly with the acid to produce a neutral salt and carbonic acid. The carbonic acid then rapidly undergoes a decomposition reaction for form carbon dioxide and water.
500
A general term specific for a substance that refers to the amount of heat required to raise the temperature of one gram of material by one degree Celsius
Specific Heat
500
What effect does dissolved salt have on the freezing point of water? Explain.
Lowers the freezing point. The salt interferes with the water molecules' ability to arrange themselves in the crystalline lattice. More energy must be removed from the water in order for the molecules to lock so the freezing point is reduced.
500
Name the 3 fundamental methods of heat transfer
1. Conduction 2. Convection 3. Radiation
500
State 4 common food substances that contain an acidic substance
1. Vinegar 2. Brown sugar 3. Buttermilk 4. Lemon juice
500
Which is more effective as a leavening agent? Steam or Air? Why?
Steam because air only expands 1/273 of it volume for each Celsius degree increase whereas the volume of water expands 1,600 times as it vaporizes