What mass of hg will occupy a volume of 75.0 ml?

75.0 mL in liters:

75.0 / 1000 => 0.075 L

1 mole 22.4 L ( at STP)
( moles Hg) 0.075 L

moles Hg = 0.075 x 1 / 22.4

moles = 0.075 / 22.4

= 0.00334 moles of Hg

Hg => 200.59 u

1 mole Hg 200.59 g
0.00334 moles Hg ( mass Hg )

mass Hg = 200.59 x 0.00334 / 1

mass Hg = 0.6699 / 1

= 0.6699 g of Hg

The correct answer is a