8.49

[Megan Purl 1E]

The question reads:
OF2 (g) + H2O (g) --> O2 (g) + 2 HF (g) delta H = -318 kJ
What is the change in internal energy for the reaction of 1.00 mol OF2?

I understand the process of how to solve for this equation but in the solutions manual it solves using PV=nRT and it plugs in T as 298K. I was just wondering how that number was calculated because it doesn't state the temperature in the problem.

[Shane Simon 2K]

Whenever no temperature is given but a temperature is needed to solve, you assume the temperature is 25.0 degrees Celcius which is 298 K.

[Oscar Valdovinos 1I]

I think you assume ideal gases, which is why we use Pv=nRT. Also in ideal gases tempature is always 25 degrees celsius or 298 kelvin

[Helen Shi 1J]

Since using Kelvin or Celcius will give different answers, which one should we use?

[Varsha Swamy 2J]

I think we should use Kelvin in problems where it makes a difference because that is the SI unit for temperature.
For problems where the equation just asks for a change in temperature, using Kelvin or Celsius will yield the same result.

[Matthew Lin 2C]

Since using Kelvin or Celcius will give different answers, which one should we use?

I would definitely use Kelvin, but if you're only calculating the change in temperature, you can use either Kelvin or Celsius.