Question

What is the effect would an impurity in the unknown solid have on the molecular weight...

What is the effect would an impurity in the unknown solid have on the molecular weight determination?

Homework Answers

Answer #1

You haven’t mentioned how you determined the molecular weight of the unknown solid; I shall assume gravimetry as it is one of the most commonly used techniques for molecular weight determination.

We must assume that the impurity is inert to all the reactions that the sample containing the unknown solid went through and is present in the thoroughly washed and dried residue that is obtained in the final step for the molecular weight determination. The impurity shall increase the dry weight of the solid in the crucible. The molecular weight obtained by converting this weight into number of moles will be higher, since we had an erroneous higher weight than is actually true.

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
What would be the effect of each of the following on the calculated molecular weight of...
What would be the effect of each of the following on the calculated molecular weight of the solute? A)some cyclohexane evaporated while the freezing point of pure cuclohexane was being measured. B)some cyclohexane evaporated after the solute was added. C)a foreign solute was already present in the cyclohexane. D) the thermometer is not calibrated correctly.it gives a temperature that is 1.5 c too low at all temperatures
You wish to determine the molecular weight of an unknown biomolecule. It is slightly soluble in...
You wish to determine the molecular weight of an unknown biomolecule. It is slightly soluble in hexane; you are able to dissolve 10.0 mg in 100 mL of hexane. 1) If your osmometer can measure a pressure difference as low as 0.1 Torr, what is the maximum molecular weight you could measure? 2) If your osmometer measures the difference in height across the semipermeable membrane, what is the maximum molecular weight you could measure, assuming you can detect as small...
I am looking for the molecular weight of an unknown acid in a titration. My acid...
I am looking for the molecular weight of an unknown acid in a titration. My acid is diprotic, the equivalence points are at 1.4 mL (of NaOH added) and 3 mL (of NaOH added). The molarity of NaOH is 0.98 M. I used 0.025 g of the unknown acid in the titration. How do I find the molecular weight of the unknown acid?
Molarity of NaOH and molecular weight of the unknown acid Part A Run 1 Run 2...
Molarity of NaOH and molecular weight of the unknown acid Part A Run 1 Run 2 Mass of H2C2O4*2H20 used in grams 0.2127 0.2124 Moles of H2C2O4*2H2O (mol) 1.69 *10^-5 1.69*10^-5 Number of protons available for reaction with OH- 2H 2H Moles of OH- which reacted (mol) 2 2 Volume of NaOH solution used (mL) 18.71 19.15 Molarity of NaOH soultion (M) .12 .12 Average molarity of NaOH (M) Part B with unkown sample Run 1 Run2 Mass of unknown...
Suppose some of your unknown sample has failed to dissolve even after you have titrated to...
Suppose some of your unknown sample has failed to dissolve even after you have titrated to your end point. What effect would this have on the calculated molecular weight of your unknown? Explain.
How do you calculate the molecular weight of an unknown salt given the concentration and known...
How do you calculate the molecular weight of an unknown salt given the concentration and known mass? Unknown starting mass: 0.0484g Unknown concentration: 0.00552 mM
Diffusion experiment: What would diffuse faster, a low molecular weight dye, or a high molecular weight...
Diffusion experiment: What would diffuse faster, a low molecular weight dye, or a high molecular weight dye? Why did you need to keep refilling the dye in the well? Would it change your result if you ran out of dye during the experiment? When diffusion occurs, there needs to be a difference of molecules in the two areas. Molecules move from high concentration to where they are in lower concentration. This is called what?
What effect would the initial color of a tested solution have on your determination of the...
What effect would the initial color of a tested solution have on your determination of the pH? For example, what effect would the purple color of grape juice have on your determination?
When dissolved in 100 g of solvent whose molecular weight is 94.10 and whose freezing point...
When dissolved in 100 g of solvent whose molecular weight is 94.10 and whose freezing point is 45 ºC, 0.5550 g of solute of molecular weight 110.1 gave in freezing point of depression of 0.382 ºC. Again, the 0.4372 g of solute of unknown molecular weight has dissolved in 96.50 g of solvent, freezing point lowering was found to be 0.467 ºC . Find the molecular weight of the unknown state.
Acetic acid (molecular weight = 60.05 g/mol) and sodium acetate (molecular weight = 82.03 g/mol) can...
Acetic acid (molecular weight = 60.05 g/mol) and sodium acetate (molecular weight = 82.03 g/mol) can form a buffer with an acidic pH. In a 500.0 mL volumetric flask, the following components were added together and mixed well, and then diluted to the 500.0 mL mark: 100.0 mL of 0.300 M acetic acid, 1.00 g of sodium acetate, and 0.16 g of solid NaOH (molecular weight = 40.00 g/mol). What is the final pH? The Ka value for acetic acid...