Chemistry Question?

[fris]

Commercial (concentrated) ammonium hydroxide solution, NH4OH, is 27.0% m/m. The specific
gravity of the solution is 0.900. What volume (in mL) of this solution contains 45.0 g of NH4OH?

 

[skipper]

1 ml has a mass of 0.900 g and contains 0.270x0.900 g NH4OH (0.243 g)
45.0 g / 0.243 g/mL = 185 mL