### Practice Midterm #3A

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**Sun Feb 11, 2018 8:55 pm**Lex Luthor is trying to design a gaseous mixture of Krypton gas and Helium gas to make Superman weak and have a high voice at the same time! But first, he wants to quickly review entropy. He finds a sealed box that has two compartments. He puts 9.00 g of Helium gas in the first compartment, and 125g of Krypton gas in the second compartment. The compartment with Krypton is 3 times the size of the compartment with Helium (triple the volume). He then removes the separating divider, allowing the gases to mix, and sees that temperature then increases from 50.0 to 75.0 oC.

A) Assuming the gases are ideal monatomic gases throughout the process, what is the total change in entropy of the system?

I cannot figure out which equations for entropy to use for this problem. Any help would be great.

A) Assuming the gases are ideal monatomic gases throughout the process, what is the total change in entropy of the system?

I cannot figure out which equations for entropy to use for this problem. Any help would be great.