we will use the root mean squared speed of oxygen formula v= (3RT) / M T= vM/3R where v =1.12x104 m/s; velocity R= (8.31447 kg m2 s-2 K-1 mol-1) gas constant
M = 0.0319988 kg/mol; molar mass of oxygen
substituting the given values, we will get
T(K)= 14.37K or -258.78 C
Oxygen molecules speed of 1.12x104 m/s is at temperature -258.78C.