amoon6818

Carbon dioxide (CO2) is an interesting substance. It has no
liquid phase at normal pressure; it sublimates rather thanmelts,
going directly from the solid form (dry ice) to a vapor. This
sublimation occurs at -78.5°C with a heat of sublimation(similar
to a heat of vaporization) of 573,100 J/kg.
A) Draw the phase diagram (T vs. Q) for a 1kg sample ofcarbon
dioxide that covers the temperature range from -125°C to-25°C.
B) Calculate the total amount of heat required to raise the
temperature of the sample from -125°C to -25°. The specificheat
of solid dry ice is 815 J/kg C° and for the vapor is 2 J/kg C°.

The quantity of heat Q that changes the temperature ?T of a mass mof a substance is given by Q = mc?T, where c is the specific heatcapacity of the substance. For example, for H20, c = 1 cal/g°C. Andfor a change of phase the quantity of heat Q that changes the phaseof a mass m is Q = mL, where L is the heat of fusion or heat ofvaporization of the substance. For example, for H20 the heat offusion is 80 cal/g or 80 kcal/kg, and the heat of vaporization is540 cal/g or 540 kcal/kg. Use these relationships to determine thenumber of calories to change

Heat energy. As an attentive scientist, you put heat into a 0.500kg sample of solid material at the rate of 10.0 kJ/min whilerecording its temperature as a function of tiriie. You plot yourdata - temperature (in Celsius) on the y-axis, and time (inminutes) on the x-axis - and obtain the graph shown.

a. What is the latent heat of fusion for this substance?

b. What are the specific heat capacities of the liquid and solidstates of the material?

An experiment measures the temperature of a 500g substance whilesteadily supplying heat to it. The figure shows the results of theexperiment.

http://session.masteringphysics.com/problemAsset/1074011/4/knight_Figure_17_42.jpg

a) What is the specific heat of the solid phase?
b) What is the specific heat of the liquid phase?
c) What is the heat of fusion?
d) What is the heat of vaporization?

what  is heat?

The readings are concerned with the post-World War II American economy; the 'Golden Age' of American capitalism is regarded as lasting from around 1945 to 1973. Regarding this task:

1- Identify and explain at least two of the good characteristics of this time period that gave rise to the title "Golden Age" (explain why this time period was unique).