How many grams of concentrated nitric acid solution should be used to prepare `250 mL` of `2.0 M HNO_(3)`? The concentrated acid is `70% HNO_(3)`:

Options

A. 70.0 g. conc. `HNO_(3)`
B. 54.0 g of conc. `HNO_(3)`
C. 45.0 g conc. `HNO_(3)`
D. 90.0 g conc. `HNO_(3)`

Answer

C

Explanation

Molarity `=("Moles of " HNO_(3))/("Volume") xx 1000`
`=(2.0 xx 250)/1000 = 0.5`
Mass of `HNO_(3) = 0.5 xx 63 = 31.5`g