CHEMISTRY COMMUNITY

sahajgill

15.65 For the reversible, one-step reaction 2A ⇌ B + C, the forward rate constant for the formation of B is 265 L.mol^-1.min^-1 and the rate constant for the reverse reaction is 392 L.mol^-1.min^-1. The activation energy for the forward reaction is 39.7 kJ.mol^-1 and that of the reverse reaction is ...

sahajgill

The positional disorder in COF2 is greater than in BF3 because BF3 can only be arranged in one way--with B as the central atom connected to 3 F atoms. However, COF2 can be arranged in three different ways, giving it a higher molar entropy than BF3 as can be seen through the equation S = k ln(W)

sahajgill

Since the system is isothermal, we know that the change in internal energy is 0. So q+w=0, and q=-w. Since the balloon is expanding its volume against a changing pressure, work is being done. This also means that the energy lost during work is gained as heat, because the internal energy must stay 0....

sahajgill

There is no 2Br in the equation

sahajgill

No, all the information needed from appendex b would be provided if this question was on a test or exam.

sahajgill

I am confused as to how the chemical equation on 14.1, Part D was balanced.

sahajgill

I don't think number 55 is part of what is covered on the midterm, but to solve it, you have to use the ice box method

sahajgill

It is under the "Administrative Questions and Class Announcements" topic. Here is the link

viewtopic.php?f=160&t=27112

sahajgill

No, we never need to know the derivations, they are just used to help us understand the formulas

sahajgill

Why is container A's entropy is higher than container C's entropy if Container A's atoms are monatomic while C's atoms are diatomic? If they're diatomic, doesn't it make it a bit more complex?

sahajgill

I don't really understand how to set up number 53, how do I set up the balanced equation?

sahajgill

Yes, this is true for gaseous products. However, if there are a different amount of moles in a different phase, the answer could be different

sahajgill

It's an isolated system because no energy or matter is exchanged between the calorimeter and the surroundings.

sahajgill

A C-C bond is formed because when the double bond C=C is broken, the C-C bond has to be reformed. It is not possible for one of the C=C bonds to be broken only. You are right about the C-H bond, but the other bond that forms is C-OH, which is not a double bond.

sahajgill

I did this question by using the bond enthalpies. The total enthalpy required to break the bonds was 684 kj.mol^-1 but the total enthalpy of the formation of the bonds was -926 kj.mol^-1 and is negative since when bonds form, it is an exothermic process. Add -926 to 684 and you get -242 kj.mol^-1

sahajgill

Qp is constant pressure while Qv is constant volume

sahajgill

In question number 55, the question states that "absorption takes place at the infared spectrum at 3600cm^-1. Is this referring to the wavelength, or the diameter?

sahajgill

it doesn't have wavelike properties because it is too small to detect. the threshold is anything x 10^-15 as the smallest wavelength that portrays wavelike properties

sahajgill

Also not that there are 1000 milimoles in a single mole. I saw this appear a few times throughout the homework. Try to remember the prefixes as it'll help a lot.

sahajgill

Since oxygen has the highest molar mass and occurs the most (there is only one atom of hydrogen and one atom of nitrogen but there are three oxygen atoms in the molecule), you can assume that the element that occurs with the greatest mass percentage is oxygen.

CHEMISTRY COMMUNITY

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