Question

6. 2.50 grams of nicotine (C10H14N2) was dissolved in 150.0 g of dichloromethane. What is the concentration of that solution in molality? b. In mole fraction? 7. How many grams of sucrose (C12H220.1) do you need to make 500.0 mL of a 0.050M solution? 8. Some intravenous sugаr solutions are 5.0% glucose (C.H1206) by mass. How many grams of glucose are in a 1.0L IV bag if the density of the solution is 1.01 g/mL.

Answer 1

Q6. mass C₁₀H₁₄N₂ = 2.50 g

moles C₁₀H₁₄N₂ = (mass C₁₀H₁₄N₂) * (molar mass C₁₀H₁₄N₂)

moles C₁₀H₁₄N₂ = (2.50 g) / (162.23 g/mol)

moles C₁₀H₁₄N₂ = 0.01541 mol

mass dichloromethane = 150.0 g = 0.1500 kg

molality C₁₀H₁₄N₂ = (moles C₁₀H₁₄N₂) / (mass dichloromethane in kg)

molality C₁₀H₁₄N₂ = (0.01541 mol) / (0.1500 kg)

molality C₁₀H₁₄N₂ = 0.103 m

(b) mass dichloromethane = 150.0 g

moles CH₂Cl₂ = (mass CH₂Cl₂) / (molar mass CH₂Cl₂)

moles CH₂Cl₂ = (150.0 g) / (84.93 g/mol)

moles CH₂Cl₂ = 1.766 mol

Total moles = (moles CH₂Cl₂) + (moles C₁₀H₁₄N₂)

Total moles = (1.766 mol) + (0.01541 mol)

Total moles = 1.7816 mol

mole fraction C₁₀H₁₄N₂ = (moles C₁₀H₁₄N₂) / (total moles)

mole fraction C₁₀H₁₄N₂ = (0.01541 mol) / (1.7816 mol)

mole fraction C₁₀H₁₄N₂ = 0.00865

Q7. concentration sucrose = 0.050 M

volume sucrose solution = 500.0 mL = 0.5000 L

moles sucrose = (concentration sucrose) * (volume sucrose solution in Liter)

moles sucrose = (0.050 M) * (0.5000 L)

moles sucrose = 0.025 mol

mass sucrose = (moles sucrose) * (molar mass sucrose)

mass sucrose = (0.025 mol) * (342.3 g/mol)

mass sucrose = 8.56 g

Q8. volume of IV liquid = 1.0 L = 1000 mL

mass of IV liquid = (volume of IV liquid) * (density of IV liquid)

mass of IV liquid = (1000 mL) * (1.01 g/mL)

mass of IV liquid = 1010 g

mass percent glucose = 5.0 %

mass fraction glucose = (mass percent glucose) / 100

mass fraction glucose = (5.0) / 100

mass fraction glucose = 0.050

mass of glucose in IV = (mass fraction glucose) * (mass of IV liquid)

mass of glucose in IV = (0.050) * (1010 g)

mass of glucose in IV = 50.5 g