contestada

A 1.124 g sample contains only vitamin C (CHO) and sucralose C, H,,C1,0). When the sample is dissolved in water to a total volume of 43.4 ml, the osmotic pressure of the solution is 3.04 atm at 295 K. What is the mass percent of vitamin C and sucralose in the sample?

Respuesta :

Edufirst

Answer:

           [tex]Vitaminc\text{ }C:73.8\%\\ \\ Sucralose:26.2\%[/tex]

Explanation:

1. Molar masses of the two compounds

i) Vitamin C:

Formula: C₆H₈O₆

  • Molar mass: 176.13 g/mol

ii) Sucralose

  • Formula: C₁₂H₁₉Cl₃O₈
  • Molar mass: 397.64 g/mol

2. Molarity of the solution:

The osmotic pressure is a colligative property which can be calculated using the following equation:

           [tex]\Pi =MRT[/tex]

Where:

  •   Π is osmotic pressure (atm) = 3.04 atm
  •    M is the molar concentration of dissolved species (mol/L).
  •    R is the ideal gas constant = 0.08206 L-atm/mol- K
  •    T is the temperature (Kelvin) = 295 K

You can solve for M:

         [tex]M=\Pi/(RT)=\frac{3.04atm}{0.08206(atm\times L/K\times mol)\times295K}\\ \\ M=0.1256[/tex]

3. Number of moles

You can calculate the number of moles of the dissolved species using the formula:

        [tex]M=number \text{ }of \text{ }moles/volume(in\text{ }liters)}[/tex]

        [tex]0.1256M=number \text{ }of \text{ }moles/0.0434L\\\\number \text{ }of \text{ }moles=0.1256M\times 0.0434L=0.0054502mol[/tex]

3. Equation to find moles of each compound

Number of moles of each compound:

i) Vitamin C

Let x be the mass in grams of vitamin C in the 1.124g sample. Then, 1.124g - x is the mass of sucralose.

  • Number of moles = mass in grams / molar mass
  • Number of moles = x / 176.13 g/mol = x / 176.13

ii) Sucralose

  • Number of moles = (1.124g - x) / 397.64 g/mol = (1.124 - x / 397.64)

iii) Total moles equation:

            [tex]x/176.13+(1.124-x)/397.64=0.0054502[/tex]

  • Solve for x:

                   [tex]x=0.8295[/tex]

Then,

                  [tex]1.124-x=0.2945[/tex]

And the mass percent of vitamin C and sucralose are:

        [tex]Vitaminc\text{ }C:0.8295g/1.124g\times 100=73.8\%\\ \\ Sucralose:0.2945g/1.124g\times 100=26.2\%[/tex]

Otras preguntas