Question

Find the temperature change of 16 g of oxygen gas during an internal energy change of 1515 cal.
(Given degree of freedom of oxygen is 5 and 1 Cal= 4.2 J)

• A. 612 K
• B. 550 K
• C. 320 K
• D. 670 K

Answer 1

The correct option is A 612 K

Since, we know $\Delta U=\frac{f}{2}nRdT$
where $\Delta U$= internal energy change of the gas
n = number of moles of gas = $\frac{16}{32}$ = 0.5 moles
We know, f = degree of freedom = 5
$\Delta U=\frac{5}{2}\times 0.5\times 8.314\times dT$
So, $1515\times 4.2=6363=\frac{5}{2}\times 0.5\times 8.314\times \Delta T$
On solving,
$\Delta T=612$