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

Answer

B

Explanation

`M=(Wxx1000)/(M_(w)xxV_("solution (mL)"))`
`2=(Wxx1000)/(63xx250)`
W = 31.5 g
70% `HNO_(3)` means 70g `HNO_(3)` is present in 100g = 45g of solution