Sec 10.1: “Energy Transfer”
1. A sample can _________________ energy to another ________________.
a. Examples of energy transfer are electric _____________ in a wire, a beam of
_________, a moving ____________, and a ____________ used by a welder.
2. One of the simplest ways energy is transferred is as _________.
a. Heat: the ____________ transferred between objects that are at
__________________ ______________.
b. Energy is measured in _________________.
3. The amount of energy transferred from one sample must be ____________ to the
amount of energy _________________ by a second sample.
a. The _____________ energy of the two samples remains exactly the _________.
b. Which law is this? _______________________________________________
4. Temperature: a measure of how ____________ (or cold) something is; specifically, a
measure of the average _____________ ___________ of the particles in an object.
a. ____________ is always transferred from the ____________ sample to the
______________ sample.
5. The temperature of a sample depends on the average _____________ energy of the
sample’s _____________.
a. The ______________ the temperature of a sample is, the ______________ the
sample’s particles move.
b. The temperature _____________ of a sample also depends on the _________ of
the sample.
c. If you add the same amount of ____________, as heat, to different
____________ of water, the sample that has __________ mass will heat up
______________.
6. Heat and Temperature are _________________.
a. Temperature is an ______________ property.
b. The temperature of the samples does ________ depend on the ______________
of the sample.
c. ___________ is an ___________ property.
d. The amount of energy transferred as _________ by a sample depends on the
_____________ of the sample.
e. Example: Both water in a glass and water in a pitcher can have the same
________________, but the water in the pitcher can transfer ____________
energy as heat because it has more ______________ than the water in the glass.
7. Enthalpy: the total ___________ content of a sample.
a. The symbol for enthalpy is: ________
b. The unit for enthalpy is: ______________
8. Molar Heat Capacity: the __________, as heat, needed to ____________ the
temperature of ________________ of the substance by 1 K.
a. Symbol: ______
b. Unit: ________
c. Molar heat capacity is accurately measured only if _____ other process, such as a
___________ ____________, occurs.
(You’re simply heating up or cooling down a sample)
9. Molar Heat Capacity Formula:
q = _________________________
n = _________________________
C = _________________________
ΔT = ________________________ (final temp – initial temp)
Energy = (# of moles) (molar heat capacity) (temperature change)
10. Calculating the Molar Heat Capacity, Sample Problem A, pg 342
Determine the energy as heat needed to increase the temperature of 10.0 mol of
mercury by 7.5 K. The value of C for mercury is 27.8 J/K∙mol.
11. Calculating the Molar Heat Capacity, practice #3, pg 342.
Calculate the energy as heat needed to increase the temperature of 0.80 mol of nitrogen,
N2, by 9.5 K. The molar heat capacity of nitrogen is 29.1 J/K∙mol.
12. Calculating the Molar Heat Capacity, Additional Practice
Energy, 4.72 J, is needed to raise the temperature of 4.00 g of gold from 20.0˚C to
30.0˚C. What is the molar heat capacity for gold?
13. “About 25 Rule”
a. The molar heat capacities of all the ____________ are nearly the __________.
b. When 1 mol of ANY metal absorbs _________ of energy as heat, the temperature
increases by ________.
c. So, for metals, C = ______________.
14. Molar Heat Capacity is Related to _____________ _____________
a. Specific Heat: the energy, as __________, needed to raise the temperature of
_____________ of a substance by 1 K.
b. Symbol: _________
c. Unit: ___________
d. (Molar Mass) (Specific Heat) = Molar Heat Capacity
15. Molar Heat Capacity/Specific Heat Example
Use table 1 on pg. 343 to determine the specific heat of mercury (Hg).
16. Heat Results in _______________ Particle Motion
a.
When a substance receives energy in the form of heat, its ___________ and the
_______________ energy of its particles both ____________.
b. The motion of these particles is ____________.
c. If you kick a ball across a field, the ____________ you supply causes the
particles in the ball to move ______________ in the same _______________.
d. The motion of these particles is ________________.