Answer:
To find the volume of the 28.0 wt% NH3 solution required, we need to determine the amount of NH3 needed to make the 0.250 M NH3 solution and then calculate the volume using the given density.Let's start by calculating the moles of NH3 needed for the 0.250 M solution:Molarity (M) = moles (mol) / volume (L)Rearranging the equation:moles (mol) = Molarity (M) × volume (L)moles (NH3) = 0.250 M × 0.500 L= 0.125 molesNow, let's calculate the mass of NH3 needed:mass (g) = moles (mol) × molar mass (g/mol)The molar mass of NH3 is:N: 14.01 g/molH: 1.01 g/mol (x 3) = 3.03 g/molmolar mass (NH3) = 14.01 g/mol + 3.03 g/mol= 17.04 g/molmass (NH3) = 0.125 mol × 17.04 g/mol= 2.13 gFinally, let's calculate the volume of the 28.0 wt% NH3 solution required using the given density:density (g/mL) = mass (g) / volume (mL)Rearranging the equation:volume (mL) = mass (g) / density (g/mL)volume (mL) = 2.13 g / 0.899 g/mL= 2.37 mLTherefore, the volume of the 28.0 wt% NH3 solution required to make the 0.250 M NH3 solution is 2.37 mL.
Step-by-step explanation: