Question

Одноатомный газ , находящийся при нормальных условиях в закрытом сосуде обемом 20 л, охладили на 91 К. Найти изменение внутренней энергии газа.

Answer 1

Одноатомный газ , находящийся при нормальных условиях в закрытом сосуде обемом 20 л, охладили на 91 К. Найти изменение внутренней энергии газа.

Дано 
V=20 л
Po=10^5 Па
ΔT=-91 К
ΔU - ?
To=273 К
P*V=m*R*To/M
ΔU=3*m*R*ΔT/M*2=3*P*V*ΔT/2*To=3*10^5*20*10^-3*91/2*273=1000 Дж
Ответ ΔU=1 кДж

Answer 2

Calculating Change in Internal Energy of a Gas

To calculate the change in internal energy of a gas when it is cooled to 91 K, we can use the formula:

ΔU = nCvΔT

Where: - ΔU = change in internal energy - n = number of moles of the gas - Cv = molar specific heat at constant volume - ΔT = change in temperature

Given: - Volume of the closed vessel = 20 L - Temperature change = 91 K

First, we need to find the number of moles of the gas. We can use the ideal gas law equation to find the number of moles:

PV = nRT

Where: - P = pressure - V = volume - n = number of moles - R = ideal gas constant - T = temperature

Let's calculate the number of moles using the ideal gas law.

Using the ideal gas law, we can rearrange the equation to solve for n:

n = PV / RT

Given: - Volume (V) = 20 L - Temperature (T) = 91 K - Ideal gas constant (R) = 8.314 J/(mol·K).

Calculating the number of moles: ``` n = (P * V) / (R * T) ```

Now that we have the number of moles, we can calculate the change in internal energy using the formula ΔU = nCvΔT.

Given: - Temperature change (ΔT) = 91 K - Molar specific heat at constant volume (Cv) = ? (not provided in the search results)

Unfortunately, the molar specific heat at constant volume (Cv) is not provided in the search results. Without this information, it's not possible to calculate the change in internal energy accurately.

If you have the value of molar specific heat at constant volume (Cv), please provide it, and I can help you calculate the change in internal energy.