What gives us the ability to do work or cause change?
What is energy
Mechanical Energy is the ______ or total of the potential and kinetic energy in an object.
Sum
Harry uses a pulley to put up a bucket of water from a well. What energy transformation takes place as the bucket is lifted up out of the well?
As the bucket rises, kinetic energy is transformed to potential energy
The Law of Conservation of Energy tells us that Energy is not _________________ . It can only be _________ from one kind of energy to another.
created nor destroyed. transformeed
What is calorimetry? What is the device used to measure this?
The science of measuring heat transfer when a substance absorbs or gives off heat; calorimeter.
What kind of energy transformation takes place in a campfire?
Chemical energy is transformed into heat and light energy
At what point does a roller coaster have the most kinetic energy?
At the bottom of the biggest hill
The enthalpy change of a reaction can be calculated using the following equation:
ΔH = (sum of enthalpies of reactants) - (sum of enthalpies of products)
As something gets lifted higher off the ground, its _______ _______ increases
Potential Energy
The type of energy that travels in waves. What is it?
Electromagnetic
At the melting point of a substance, temperature ________ as heat is being added and the substance is changing from a solid to a liquid.
Remains constant
Given that the enthalpy of fusion for water is 334 J/g. Find the mass of water that has been converted to ice if the heat released was equal to 7800 J.
24 g
Iron is the heaviest metal vaporized in the sun. Its (delta)Hvap is 6071.43 J/g. How much heat is needed to turn (keep) .5 kilogram of iron into a gas?
3 x 106 J
A 75-kg refrigerator is located on the 70th floor of a skyscraper (300 meters above the ground) What is the potential energy of the refrigerator?
2 x 105 J
What is the final temperature when 640. calories are given off by 40.0 g of water at 45.0 °C ?
29.0 °C
Draw the molecule:
CH3COOC2H5
Mr. Gonzalez will determine the winner.
Calculate the enthalpy in the reaction below:
C2H2 (g) + 2H2 (g) --> C2H6(g)
H-H (432 kJ/mol)
C(triple)C (839 kJ/mol)
C-H (413 kJ/mol)
C-C (347 kJ/mol)
-296 kJ/mol; exothermic
A 4.50 g coin of copper absorbed 54 calories of heat. What was the final temperature of the copper if the initial temperature was 25°C? The specific heat of copper is 0.092 cal/g°C.
160°C
How much energy is required for the reaction to occur?
(Mr. G will show you the diagram)
200 kJ
Calculate the bond enthalpy for the reaction:
CH3CH2CH3 (g) + 5O2 (g) --> 3 CO2 (g) + 4 H2O (g)
Exo or Endo?
-2057 kJ/mol
Exothermic