Question

Commercial sample of concentrated
nitric acid labeled 63% by mass has
density 1.4 g ml^-1.The molarity of
HNO3 sample is
(a) 28 M
(b) 14 M
(c) 10 M
(d) 7 M

plz answer with steps ​

Answer 1

Answer:

c) 10 M

hope you understand

Answer 2

Explanation

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in an aqueous solution. This means that 68 g of nitric acid is dissolved in 100 g of the solution.

Molar mass of nitric acid (HNO3) = 1 × 1 + 1 × 14 + 3 × 16 = 63 g mol - 1

Then, number of moles of HNO3 = 68 / 63 mol

= 1.08 mol

Also density = 1.504g/mL-1 (given)

Therefore from the formula density = mass / volume,we get

Volume of solution = 1000/1.504 = 66.49 mL

Therefore molarity of nitric acid = (1.08/66.49) x 1000 = 16.24 M