If a 5.0 mL test tube has a concentration of 0.051 M iron, what is the mass of iron (in mg) in the test tube

Question

please help!!!

Answer 1

0.051 moles/L x 0.005 L = 0.000255 moles x 55.8 g/mole = 0.01423 g x 1000 mg/g = 14.2 mg = 14 mg (to 2 sig. figs.)