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

Answer

B

Explanation

250 mL of 2.0 M `HNO_(3)` will contain
`=(2)/(1000)xx250=0.5 "mol"`
`0.5xx63=31.5g`
As concentrated `HNO_(3)` is `70%`
`therefore" concentrated " HNO_(3)` required
`=(100)/(70)xx31.5g=45g`