The correct answer is:
Dilute 170 mL of the concentrated reagent to 900 mL with water.
To prepare 900 mL of 3.00 M HNO3 solution, we need to calculate the amount of HNO3 in the 70.5% HNO3 reagent.
First, determine the mass of HNO3 in the 170 mL of the concentrated reagent:
170 mL x 0.705 = 119.85 g of HNO3
Next, calculate the moles of HNO3 in 119.85 g:
119.85 g / 63.01 g/mol = 1.903 moles
Now, use the formula M1V1 = M2V2 to dilute the solution:
(1.903 moles / 0.900 L) = (3.00 M / 0.900 L)
1.903 moles = 2.667 moles
So, you will need to dilute 170 mL of the concentrated reagent to a total volume of 900 mL with water to prepare 900 mL of 3.00 M HNO3.