Archive for the ‘Chemistry’ Category

What fraction of energy is used to change the internal energy of water?

Tuesday, November 3rd, 2009

khuezi asked: The molar enthalpy of vaporization of water at 373 K is 41.16 kJ/mol. What fraction of this energy is used to change the internal energy of the water? (Assume that water vapor is an ideal gas.) What fraction is used to do work against the atmosphere? What equation do I ...

What is the difference between standard gibbs free energy change and gibbs free energy change?

Tuesday, October 27th, 2009

Brian H asked: I am confused between standard gibbs free energy change and gibbs free energy change. Aren't both the change in gibbs free energy of the system when reactants are converted completely, or 100 %, to products? Why does the change in gibbs free energy of the reaction change ...

What happens to this energy when the ball lands in a sand trap?

Tuesday, October 13th, 2009

Ben and Jerry's asked: How many of the following happens? The kinetic energy is transferred to the air. The kinetic energy is transferred to the sand. Its speed drops to zero. Its speed increases. Energy is consumed. Energy is released. The ball expands due to heat increase. The ball is deformedCARMEN

How energy intensive is it to maintain a vacuum?

Thursday, September 3rd, 2009

Brian L asked: This is for extracting various alcohols and water from a solution without having to maintain the solution at a very high temperature. I think it might be less energy intensive this way, but I have no data on energy needed to maintain a vaccum. What ...

How much energy as heat must be transferred to raise the temperature of a 55 g sample of aluminum foil from?

Wednesday, September 2nd, 2009

Luv2singnbling asked: How much energy as heat must be transferred to raise the temperature of a 55 g sample of aluminum foil from? How much energy as heat must be transferred to raise the temperature of a 55 g sample of aluminum foil from? How much energy as heat must be transferred ...