Question

The universal gas constant is 8.31451 J/K · mol. Calculate the change in internal energy of 7 mol of helium gas when its temperature is increased by 4.9 K. Answer in units of J.

Answer 1

Answer:

Change in internal energy of the gas is given as

$\Delta U = 427.8 J$

Explanation:

change in internal energy of the ideal gas is given as

$\Delta U = \frac{f}{2}nR\Delta T$

here we know that

n = 7 mol

R = 8.31451 J/K-mol

$\Delta T = 4.9 k$

since we know that Helium gas is a monoatomic gas so we have

$f = 3$

now we have

$\Delta U = \frac{3}{2}(7)(8.31451)(4.9)$

$\Delta U = 427.8 J$