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I'm still struggling. I've calculated the grams of Na2S2O3 = 1.58 g, but I'm still confused as to how I get the molarity of S2O3

It does not give the number of moles per trial. The question written above is all the information given. The total volume is 7.00 mL. Is that how much volume of finished solution would be in each trial?

Homework Statement If you dissolve 9 g of urea (60.06 g/mol) in 10 mL of water, what is the vapor pressure of the solution at 24 C? Assume the density of water is 1.00 g/mL and the vapor pressure of pure water at 24 C is 22.4 mmHg. Homework Equations Henry's Law, maybe? I'm not sure...

Homework Statement Wine that is 28.4% ethanol by wt is set outside. Will it freeze if the temp drops to -10 C? (assume water is the solvent) Homework Equations \DeltaTfp = kfp*molality of solute The Attempt at a Solution 2.84 g of ethanol/10 g total =.284 mole \DeltaTfp= -10 ?

Homework Statement What mass of O2 can dissolve in 1L of water @ 25 C if the partial pressure of O2 is 40 mmHg? Homework Equations Henry's Law: partial pressure = kH*concentration kH of O2 = 769.2 L*atm/mol The Attempt at a Solution 40 mmHg / 769.2 = concentration

Homework Statement A 10% (by wt) solution of KNO3 would have what molality and what mole fraction Homework Equations mole fraction = moles of KNO3/total moles wt % = # g of solute/total g molality = # moles KNO3/kg H2O The Attempt at a Solution 1 g KNO3/10 g total 1 g KNO3/101.1...

Homework Statement Describe in detail how you would prepare 250 mL of a .25 molal solution of CaCl2 Homework Equations CaCl2: 110.98 g/mol molality = #moles of solute/kg of solvent

Can anyone help me out with this? I'm stuck.

So the correct unit is a Newton?

Yes? No?

Assuming, I should use the formula given by the teacher. the units are: V/C*m, right?

Hmm. Well that's really not that helpful to me. Do you have a hint on what I should do? I mean, I wouldn't be asking on this forum if I wasn't in need of help.

Hey thanks. My new number is 12.16 g of K2S2O8. Would that change my answer to: Using the balance, measure out 12.16 g of K2S2O8. Add that to a volumetric flask. Pour DI water into the flask, until 250 mL has been reached. Does that sound correct?

This was the formula we were given to calculate Lamda: Lambda = 9.99 V / [2*ke*ln(.0860 m / .0055 m)]

It does. Lambda = 9.99 V / [2*ke*ln(.0860 m / .0055 m)] ke = Coulomb's Constant, C I think that makes its V/C*m