[vanillachyrae]

1. How many milliliters of a 1.500M aqueous solution of Fe4[Fe(CN)6]3 are needed to prepare 860.0 mL of a solution that has pFe+3 of 2.50?

2. A solution contains 69.5% HNO3 (MM = 63.02) by mass and a density of 1.42 g/ml. How many mL of H2O must be used to dilute 20.0mL of this solution to prepare a 2.00M HNO3 solution?

3. Concentrated NH3 is 28% by mass and has a density of 0.90g/ml. (a) How many grams of concentrated NH3 should be used to prepare 1.50L of 0.600M NH3 solution? (b) How many mL of concentrated NH3 should be used to prepare this solution? (c) What is the resulting concentration of a 2.5 L solution prepared from 1.50 L of 6M NH3?

Can you please show the steps? I'm really confused with how to start answering these problems.
Thanks in advance.

[Borek]

You have to show your attempts at solving the question to receive help. This is a forum policy.

If you have no idea how to start, at least list known equations, knowns and unknowns.