The physician orders cefoxitin sodium 1 g q 4h IV for your p…

The physician orders cefoxitin sodium 1 g q 4h IV for your postpartum cesarean birth patient who has developed a wound infection.  The vial of cefoxitin sodium powder for injection has been reconstituted with sterile water to a concentration of 20 mg/ml.  How many milliliters of sterile water will be needed to achieve the ordered dose?