Question

An aqueous ethylene glycol (HOCH2CH2OH, FW = 62.07 g/mol) solution with a mass of 279.1 mg...

An aqueous ethylene glycol (HOCH2CH2OH, FW = 62.07 g/mol) solution with a mass of 279.1 mg is titrated with 42.9 mL of 0.0939 M Ce4 in 4 M HClO4. The solution is held at 60°C for 15 minutes to oxidize the ethylene glycol to formic acid (HCO2H) and carbon dioxide. The excess Ce4 is titrated with 11.89 mL of 0.0417 M Fe2 to a ferroin end point. What is the mass percent of ethylene glycol in the unknown solution?

Homework Answers

Answer #1

mol of Ce4 used = MV = 42.9*0.0939 = 4.02831 mmol of Ce4

mol of Ce4 excess = use formula:

Fe2+ + Ce4+ Fe3+ + Ce3+

so ratio is 1:1

mmol of Fe2 = MV = 11.89*0.0417 = 0.495813 mmol of Fe+2

then, 0.495813 mmol of Ce+4 where initially left

so

actual Ce+4 used in reaction = initial - leftover = 4.02831 -0.495813 = 3.532497 mmol of Ce+4 used in oxidation

then, mmol of EG = 1:1 ratio with respec tto ce4+

3.532497 mmol of EG

mass of EG = mmol*MW = (3.532497)*62.07 = 219.26 grams of EG

%composition = mass of EG / tota mass of sample * 100%

%EG composition = 219.26 / 279.1 *100 = 78.559 %

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
1) A 1.0-L of an aqueous solution of ethylene glycol, HOCH2CH2OH, is 60% HOCH2CH2OH by mass...
1) A 1.0-L of an aqueous solution of ethylene glycol, HOCH2CH2OH, is 60% HOCH2CH2OH by mass and has a density of 1.15 g/mL. Calculate the molality of the solution.
7. What is the mass percent of ethylene glycol (HOCH2CH2OH) in a solution of ethylene glycol...
7. What is the mass percent of ethylene glycol (HOCH2CH2OH) in a solution of ethylene glycol in water that has a freezing point of –19.2°C? (Kf for water is 1.858°C/m.) A) 99.8% B) 39.1% C) 64.1% D) 60.1% E) 10.3%
Different Ways of Expressing Concentration An aqueous antifreeze solution is 35.5% ethylene glycol (C2H6O2) by mass....
Different Ways of Expressing Concentration An aqueous antifreeze solution is 35.5% ethylene glycol (C2H6O2) by mass. The density of the solution is 1.045 g/cm3. Calculate the molality of the ethylene glycol. 8.87 m Calculate the molarity of the ethylene glycol. Calculate the mole fraction of ethylene glycol
Determine the required concentration (in percent by mass) for an aqueous ethylene glycol solution to have...
Determine the required concentration (in percent by mass) for an aqueous ethylene glycol solution to have a boiling point of 104.0C . What is its freezing point?
1.) Indicate which aqueous solution has the lowest vapor pressure: a. 0.2 M MgCl2   b. 0.1...
1.) Indicate which aqueous solution has the lowest vapor pressure: a. 0.2 M MgCl2   b. 0.1 M MgCl2   c. 0.2 M NaCl d. 0.1 M KCl e. 0.1 M Na2CO3 2.) Indicate which aqueous solution has the fastest evaporation rate. a. 0.2 M MgCl2   b. 0.1 M MgCl2   c. 0.2 M NaCl d. 0.1 M KCl e. 0.1 M Na2CO3 3.) What is the molarity of a sucrose (C12H22O11) solution that produces an osmotic pressure of 2.65 atm at 25°C?...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT