Question

Iwish to prepare 3% NH3 from 20ml strong NH4OH and 180ml H2O.Can you help me?

Answer 1

What strength is the "strong" NH3. Concentrated NH3 as it comes out of the bottle is about = 14.8 mol/L soln and that 14.8 x 17 = about 252 g/1000 mL or 25.2/100 mL or about 25.2% (that's w/v %).

So if you take the entire 20 mL and make the total volume up to 180 mL you will have about 2.8%.