Forty-four grams of CO₂ at 27^oC is mixed with 16 g of O₂ at 37^oC. The temperature of the mixture is about :

30^oC

Let t be the temperature of mixture.

Heat gained by CO₂ = Heat lost by O₂

$\Rightarrow \mu_1 C_{v_1} \Delta T_1 = \mu_2 C_{v_2} \Delta T_2$

$\Rightarrow \frac{44}{44} (3R) (t - 27) = \frac{16}{32} (\frac{5}{2}R) (37 - t)$

$\Rightarrow 3(t - 27) = \frac{5}{4}(37 - t)$

t = 30^oC