How many grams of concentated 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. 45.0g conc. `HNO_(3)`
B. 90.0g conc. `HNO_(3)`
C. 70.0g conc. `HNO_(3)`
D. 54.0g conc. `HNO_(3)`

Answer

A

Explanation

Molarity of the solution (M)
`=("mass of the solute (g)")/("moleclar mass of the solute"xx"vol. of the solution")`
or, `2=("mass of the solute (g)")/(63)xx(1000)/(250)`
`therefore`Mass of the solute `=(63)/(2)g`
Again, mass of acid `xx(70)/(100)=(63)/(2), " "therefore`Mass of acid=45g.