-Can you explain the answer, and how you got it. Enthalpy and total energy are r

Question

-Can you explain the answer, and how you got it.

Enthalpy and total energy are related in that
A) Total Energy is always greater than enthalpy
B) Enthalpy can exceed the total energy of the system
C) Enthalpy and total energy of the system can be equal
D) B and C

A Red Giant in a distant galaxy is exactly equal in distance to a Green Giant in another distant
galaxy. Characterize how the great news of their sudden disappearance will reach earth.
A) The red giant’s final light will reach earth faster because it’s light (red) has more energy than
that of green light
B) The green giant’s final light will reach earth faster because its light is higher in energy than
red light
C) All electromagnetic radiation travels at the same speed in a given medium and will hit earth
simultaneously
D) All electromagnetic light travels at 3x10^8m/s in any medium and will hit earth
simultaneously

Your chai iced tea has 5 moles of ice in it at a cool 24 degrees F. The specific heat of ice is
2.06J/gK. How much heat is needed to melt all the ice and make your drink completely watery. (show work)
A) 720 J
B) 880 J
C) 680 J
D) 810 J

Explanation / Answer

Ans 1. Enthalphy can exceed the total energy of the system and Enthalpy and total energy of the system can be equal.

Since, enthalphy = energy + delta (PV).
Therefore, correct option is D).

Ans 3. Mass of ice = 5 *18 = 90 grams.

Temperature = -4.44 degree C.

Therefore, energy required = m*c*delta (T) = 90*2.06*4.44 = 823 Joules.

Ans 2. C) All electromagnetic radiation travels at the same speed in a given medium and will hit earth
simultaneously

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