Answer
a) $0.2298 g Cr$
b) $1.32\times10^{-3} moles Fe$
c) $0.048 g Ti$
d) $8.87 moles Hg$
Work Step by Step
Using the molar mass of the element provided, we can simply convert from grams to moles or vice-versa;
a) $0.00442 moles Cr \times\frac{51.99 g/mole}{1 mole Cr} = 0.2298 g Cr$
b) $73.5 mg = 0.0735 g Fe\times\frac{1 mole Fe }{55.845 g/mole} = 1.32\times10^{-3} moles Fe$
c) $1.009\times10^{-3} moles Ti \times\frac{47.867 g/mole}{1 mole Ti} = 0.048 g Ti$
d) $1.78 kg = 1780 g Hg\times\frac{1 mole Hg }{200.59 g/mole} = 8.87 moles Hg$
