Definitions
Define a calorie
The amount of heat required to raise 1 gram of water 1 degree Celsius
What is the purpose of a calorimeter's insulation?
–q(object) = q(liquid) + q(calorimeter)
[answers may vary]
Energy is _____________ when you go from a solid --> liquid, --> gas.
What is required (absorbed, needed)?
Where is potential energy stored in chemicals?
Bonds
What is an isotope?
Two or more atoms of the same element that have different numbers of neutrons
Define Potential Energy
Energy that is stored
What is the unit for specific heat capacity?
J/gºC
When water condenses in the back of a refrigerator, the temperature will _______________.
What is increase?
Name any Noble Gas
answers may include: He; Ne; Ar; Kr; Xe; Rn;
What is the full ground state electron configuration for sulfur?
1s22s22p63s23p4
Exothermic reaction
A chemical reaction that releases energy
A 2.5-kg sample of copper (c = 0.386 J/gºC) at 24.1 ºC experiences a change in temperature to 19.7ºC. How much energy is involved?
–4,200 J
A 30,000 g of gold requires 1,890,000 J of energy to melt it. The latent heat of fusion for gold is ____________
What is 63 J/g?
What is the most electronegative element?
flourine
What is the chemical formula of barium nitrate?
Ba(NO3)2
Specific heat capacity
The amount of heat it takes to raise a specific mass of a substance 1 ºC
175.0 grams of an unknown metal gain 5.6 kJ of heat. The metal's temperature rises from 24.3 ºC to 110.5 ºC. What is the specific heat capacity of the metal in J/gºC?
The amount of energy required to completely melt a 3.0000 kg piece of ice that is initially -30.000 degrees C.
What is 1,190,270 J?
(find q -30 C to 0C then find latent heat of Ice at 0C) 1,187,400 J
Describe a calorimeter.
must list at least 3:
-Insulated
-Thermometer
-Liquid of known heat capacity
-Stirring mechanism
Balance the following chemical equation
Mg(s) + AlCl3(aq) --> Al(s) + MgCl2(aq)
3Mg(s) + 2AlCl3(aq) --> 2Al(s) + 3MgCl2(aq)
Latent heat
The amount of heat absorbed or released by a substance during a phase change
A calorimetry experiment is performed on a 112.1g sample of metal. It is heated to a temperature of 175.0 ºC and put in a calorimeter that contains 250.0g of water. If the water's temperature rises from 27.1 ºC to 31.7 ºC, what is the specific heat capacity of the metal? Ignore the calorimeter in your calculation.
The specific heat is 0.30 J/gºC.
The amount of energy required to change a 2000.0 g bucket of water at 1.000 degrees C to vapor at 140.0 degrees C. (c ice = 1.864 J/gC)
What is 5,498,000 J?
What kind of bonds connect water molecules?
Hydrogen Bonds
Give the balanced chemical equation for the complete combustion of liquid propane (C3H8).