a nurse is preparing to administer magnesium sulfate 2 g/hr iv to a client who is in preterm labor. available is 20 g magnesium sulfate in 500 ml of dextrose 5% in water (d5w). the nurse should set the iv infusion pump to administer how many ml/hr? (round the answer to the nearest whole number. use a leading zero if it applies. do not use a trailing zero.)