Can I get help on this please?

Question

A 1.180 g1.180 g sample contains only vitamin C (C6H8O6)(C6H8O6) and sucralose (C12H19Cl3O8).(C12H19Cl3O8). When the sample is dissolved in water to a total volume of 26.4 mL,26.4 mL, the osmotic pressure of the solution is 5.26 atm at 295 K. What is the mass percent of vitamin C and sucralose in the sample?

Vitamin C= ?%

Sucralose = ?%

Answer 1

Osmotic Pressure: π=RCT where C is the concentration of particles. Both of the substances are molecular so the concentration, C is just the concentration of C_C + C_S

We now know that C_c + C_S = π/(RT) = 5.26 atm/(.00821 liter-atm/mole-K * 295K) = .21718 mole/liter

We're asked for mass % so we want a way to get at masses and convert concentrations to masses per liter.

We know the sum of the masses m_C + m_S = 1.18 g

We also know that C_i = n_i/V = m_i/(M_iV) where n is moles, M is molar mass in g/mole. Now we can rewrite the osmotic pressure result as

m_C(1/M_CV) + m_S(1/M_SV) = .21718 which gives us a 2nd equation is m_C and m_S

m_C/ 176.12 + m_S/397.64 = .2178 (mole/liter)(.0264 liters) (Careful with units!)

You can solve for m_C and m_S by substitution or Gaussian elimination.

mass percent of C is 100 x m_C/(m_C+m_S) where you know the denominator already.

Please consider a tutor. take care.