Question

При изобарном расширении постоянной массы гелия при нормальном атмосферном давлении его объем увеличился на 0,2м^3. определите изменение внутренней энергии гелия. ответ выразите в кдж

Answer 1

ΔU=Q-A=((i+2)/2)*A-A=1.5*p*ΔV=1.5*10^5*0.2=30 кДж    i=3 для гелия

Answer 2

Calculating the Change in Internal Energy of Helium

When a gas undergoes an isobaric expansion, the change in its internal energy can be calculated using the formula:

ΔU = nCvΔT

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

In this case, we are given the change in volume and asked to determine the change in internal energy of helium at normal atmospheric pressure.

Determining the Change in Internal Energy

Given: - Initial volume, V1 = ? - Final volume, V2 = V1 + 0.2 m^3 - Pressure, P = normal atmospheric pressure - Change in volume, ΔV = 0.2 m^3 - Molar mass of helium, M = 4.0026 g/mol - Universal gas constant, R = 8.314 J/(mol·K)

First, we need to determine the number of moles of helium using the ideal gas law:

PV = nRT

Where: - P is the pressure - V is the volume - n is the number of moles - R is the universal gas constant - T is the temperature

Since the pressure and temperature are constant, we can rearrange the equation to solve for n:

n = PV/RT

Next, we can calculate the change in internal energy using the formula:

ΔU = nCvΔT

Where ΔT can be calculated using the ideal gas law:

ΔT = (V2 - V1)P/nR

Finally, we can substitute the values into the formula to find the change in internal energy.

Let's proceed with the calculations.