If molecular mass of gas  $A\left(M_A\right)$ is equal to molecular mass of gas  $B\left(M_B\right),$ then  $T_1>T_2.$

If  $T_1<T_2,$  then molecular mass of gas  $B\left(M_B\right)$ is necessarily less than molecular mass of gas  $A\left(M_A\right).$

If  $T_1=T_2,$ then molecular mass of gas  $B\left(M_B\right)$ is greater than molecular mass of gas $A\left(M_A\right).$ 

If gas A  is  $O_2$ and gas  B is $N_2,$  then considering them to be ideal gases,  $T_1$  is necessarily less than $T_2.$