Thermodynamics Laws

advertisement

Q=m C ∆T

Q = m L

P V = n R T

∆U = Q – W

Effic. = T h

-T c

/T c

Other Laws

W = F * d

P = W / t

P = F / A

Pre-test Study Guide

Thermodynamics Laws Vocabulary and Concepts

Kinetic Theory of Matter

Thermal Energy

Heat Flow (conduction, radiation, convection)

Internal Energy

States of matter (solid, liquid, gas)

Phase change (melting, vaporizing, condensing, etc.)

Phase change graph

Temperature and equilibrium

Temperature scales (Kelvin, Celsius, Fahrenheit)

Temperature conversions

Specific Heat Capacity

Latent Heat Capacity

Ideal Gas Laws

Isobaric, Isothermal, Isovolumetric, Adiabatic Processes

Heat Engines

Piston, cylinder, hot and cold reservoirs, exhaust

Carnot Efficiency

Actual Efficiency

MARCH 5 TH , 2012

Thermodynamics Review

Material Freezing

Point

Boiling

Point

Water 273*K

Ammonia 195 *K

Ethanol 159*K

373*K

240 *K

352 *C

Solid Specific

Heat Capacity

(C s

)

2.11 J/g *K

? (use 4.6)

2.41 J/g *K

Liquid Specific

Heat Capacity

(C s

)

4.18 J/g *K

4.6 J/g *K

2.43 J/g *K

Gas Specific

Heat Capacity

(C s

)

2.08 J/g*K

2.17 J/g *K

1.70 J/g * K

Latent Heat of Fusion (Lf)

334 J/g

339 J/g

109 J/g

Latent Heat of

Vaporization

(Lv)

2260 J/g

1369 J/g

838 J/g

16) Using the information above, create an accurate phase change graph for

Ethanol.

17) A mixture of 50g of ethanol and 50g of water start at 20*C and are heated until they’re at 120*C. How much energy is consumed in this process?

18) A gas undergoes isobaric compression. The temperature goes from 200*K to

600*K during the process. How much of its original volume does the gas now occupy?

19) An engine has a piston area of 0.1 m2 and a piston volume of 0.02 m3. It is pushed forwards at a pressure of 50,000 Pa and then has to overcome a pressure of 10,000 Pa as it returns back to its original position. How much net work is done per cycle? If it cycles 120 times per minute, how much power does it generate?

20) An engine has a hot reservoir at a temperature of 100*C and a cold reservoir of

20*C. What is the theoretical maximum (Carnot) efficiency it can achieve? If it does 100J of work for every 500J of fuel, what is its actual efficiency?

Download