Need help with chemistry question as soon as possible (assignment due very soon)

Question

"How many milliliters of a solution that is 10.85% (w/w) HNO3 with a density of 1.2630 g/mL should be diluted to make 2.00 L of a 0.225 M HNO3 solution?"

Answer 1

2.00 L x 0.225 mol / L = 0.450 moles HNO3 needed x 63.0 g HNO3 / mole = 28.35 g HNO3 needed

10.85 g HNO3 / 100 g soln x 1.263 g soln / 1 ml = 0.137 g HNO3 / ml soln

28.35 g HNO3 x 1 ml / 0.137 g HNO3 = 207 ml of the original solution

Check:

207 ml x 1.26 g / ml x 10.85% = 28.3 g HNO3 which is in agreement with the 28.35 g calculated above.

28.3 g HNO3 x 1 mol HNO3 / 63.0 g = 0.449 mols HNO3 / 2 L = 0.225 M which is what was desired