/sci/ - Science & Math

Soup /sci/,

I'm studying thermodynamics and I'm having trouble understanding what exactly enthalpy is, so I was hoping one of you brilliant motherfuckers could explain it to me.

From what I understand enthalpy is all the heat and work that is required to make place for a particular system. Is this correct? It doesn't sound right to me.

Soup /sci/,

Could one of you fine gentlemen maybe explain to me what I'm doing wrong in my calculation?

Q: Of a hypothetical fluid the standard Gibbs formation energy is 69.2 kJ/mol, the standard entropy is 437.2 J/(K mol), the molar mass is 61 g/mol and the density is 1.188 kg/dm^3. Calculate the Gibbs energy (in kJ/mol) at 34 C and 1.6 bar

My solution:
So the formula for gibbs energy at non-standard temperature and pressure equals:
<div class="math">\Delta _f G(T, p) \approx \Delta _f G^\theta (T^\theta, p^\theta)-\Delta TS^\theta + \Delta pV_m</div>

Determining all the needed variables:
<div class="math"> \Delta _f G^\theta (T^\theta, p^\theta)= 69.2 \hspace{2 mm} kJ/mol</div>
<div class="math">\Delta T = 34 - 25.15 = 8.85 K </div>
<div class="math">S^\theta = 437.2 J/(K mol)</div>
<div class="math">\Delta p = 1.6 * 10^5 - 1 * 10^5 = 6 * 10^4</div>
<div class="math">V_m = M/\rho = 61/1.188 * 10^5 = 0.051</div>

Plugging all of these variables in the equation above, gives me a value of 68.4 kJ/mol, while the answer should apparently be 65.3 kJ/mol. Can anyone see what I'm doing wrong?

Picture probably unrelated

>>4950691

Protip: rocks often have distrinct straight lines that they break apart on. Most commonly, you have joints and bedding planes.

The shit linked there is like taking a picture of a cloud that looks like something and saying that it must be a gubment conspiracy.

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