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endo or exo
Phase changes
Labs/Concepts
Mathy stuff
Heat Concepts
100
Define endothermic and exothermic reactions. Question 2.
Endothermic reactions absorb energy, exothermic reactions release energy.
100
What is the freezing point of water, in degrees celsius and kelvin? Question 4.
0 degrees celsius and 273 K.
100
True or false? According to the law of conservation of energy, energy can neither be created nor destroyed.
True
100
Question 12. What is the deltaH? Also remember it is Hproducts-Hreactants.
-261.1
100
Define temperature. Question 1.
Average kinetic energy, related to speed
200
Look at question 3 on your review. Is the left chart or right chart endothermic?
Left
200
Define these phase changes: solid-->liquid, solid-->gas. Question 7a,e
Fusion, sublimation
200
Why did we use styrofoam cups in lab?
High specific heat, doesn't change temperature easily.
200
Question 9. Will the copper or aluminum heat up faster? Why?
Copper, lower specific heat.
200
Heat is kinetic or potential energy? Is energy increasing or decreasing for a solid-->liquid transition? Question 5
Kinetic, increasing
300
Number 11. The reaction is _____________ and heat is __________ by the reaction.
Endothermic, absorbed
300
An ice cube is melted and vaporized. What property of the ice cube particles changes?
Temperature, average kinetic energy, speed of particles.
300
If delta H is negative, does it mean that the reaction is endothermic or exothermic?
Exothermic.
300
Number 13. I'm lazy. What is the specific heat?
0.004167
300
Convert 10 calories to Joules.
41.84 J
400
Baking a cake, is it endothermic or exothermic?
Endothermic
400
What does triangleHrxn mean? Question 14.
Enthalpy of reaction
400
In the lab, what did you have to calculate from the water before getting the specific heat of the metal? Q, m, C, or T?
Q
400
Question 15. I'm dead inside. What is the Q?
288 J
400
A bonfire consists of student paperwork. What is happening to the energy?
It is being released as heat.
500
Photosynthesis. Is this endothermic or exothermic? Where does energy come from?
Endothermic. Energy comes from sun
500
Going from gas to solid, what is that called? Is it endothermic or exothermic?
Deposition, exothermic.
500
What is the point of using calorimetry in lab?
Identifying unknown metals, finding calorie content in food.
500
Question 14. Lord help you. Find the C for the metal. Also c for water is 4.184.
26.6
500
A pillow and a sheet of metal are both left in the sun. Which one will heat up faster and why?
Sheet of metal, lower specific heat.