If 4 moles of an ideal monoatomic gas at temperature $400 \mathrm{~K}$ is mixed with 2 moles of another…
If 4 moles of an ideal monoatomic gas at temperature $400 \mathrm{~K}$ is mixed with 2 moles of another ideal monoatomic gas at temperature $700 \mathrm{~K}$, the temperature of the mixture is
$550^{\circ} \mathrm{C}$
$5000^{\circ} \mathrm{C}$
$550 \mathrm{~K}$
$500 \mathrm{~K}$
Solution
Temperature of the mixture
$
\begin{aligned}
T & =\frac{m_1 T_1+m_2 T_2}{m_1+m_2} \\
& =\frac{4(400)+2(700)}{4+2}=500 \mathrm{~K}
\end{aligned}
$