See the answer below.
Work Step by Step
From the ideal gas law: $m/V=PM/RT$ $M=0.082057\ L.atm/mol.K×(23+273)\ K/(715\ mmHg×1\ atm/760\ mmHg)×1.007\ g/0.452\ L $ $M=57.52\ g/mol$
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.