# Search results

1. ### Molarity homework problem

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
2. ### Molarity homework problem

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?
3. ### Vapor Pressue of the Solution

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...
4. ### Freezing Point Question

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 ?
5. ### Henry's Law

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
6. ### Chemistry Molality and Mole Fraction

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...
7. ### Preparation of a 250 mL .25 molal solution of CaCl2

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
8. ### Molarity homework problem

Can anyone help me out with this? I'm stuck.
9. ### Physics 2 Units

So the correct unit is a Newton?

Yes? No?
11. ### Physics 2 Units

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

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.
13. ### Lab Preparation Using a solid, DI water, a balance, and a flask

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?
14. ### Physics 2 Units

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

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
16. ### Physics 2 Units

cubic millimeter mm3 I think...
17. ### Lab Preparation Using a solid, DI water, a balance, and a flask

Homework Statement Describe how you would prepare exactly 250 mL of .180 M K2S2O8 solution for use. Assume that you have a supply of solid K2S2O8, deionized water, a balance, and a volumetric flask. Also, how many grams of K2S2O8 would you need? Homework Equations The Attempt at a...
18. ### Molarity homework problem

Homework Statement Calculate the initial molarity of S2O32- in each trial given that each trial has 1.00 mL of .010 M Na2S2O3 and a total volume of 7.00 mL. Homework Equations mol = g/(g/mol) M1V1=M2V2 The Attempt at a Solution (1)(.01)=7x .0014=x Homework Statement...
19. ### Physics 2 Units

Homework Statement 1) What are the units for the charge, Q? 2) What are the units for ke*Q? 3) What are the units for - ke*Q / R, R=radius (m) 4) What are the units for 2*ke*\lambda*ln R 5) What are the units for - 2*ke*\lambda 2. The attempt at a solution 1) C, Coulomb's 2) N*m2/C...
20. ### Rate Law+Temperature

Homework Statement Why is it necessary to report the temperature when reporting the rate constant? Homework Equations k*[A]^m*[B]^n The Attempt at a Solution Temperature, like the presence of a catalyst or the concentration of the substance, can have an effect on the reaction rate...
21. ### Electric Fields Lines of a pair of Finite Parallel Plates

"magnitude is double the mag due to any 1 plate" I don't understand this. Why is that so? Also, is it correct to say that (a) between the plates the distribution of charges will be uniform due to its flat nature, but (b) on the edges of the plates the distribution of charges will not be uniform...
22. ### Why are electric field lines also referred to as "lines of force"?

E=F/q By convention, the electric field vector points towards the negative and away from the positive. As far as I understand it, the decision for why an electric field vector points a certain way is a decision made by the person drawing the diagram "Think about the force on the charged object...
23. ### Electric Fields Lines of a pair of Finite Parallel Plates

Homework Statement Comment on the electric field lines of a pair of finite parallel plates (a) between the plates and (b) near the edges of the plates. Homework Equations The Attempt at a Solution
24. ### Why are electric field lines also referred to as "lines of force"?

Equipotential Lines Homework Statement What are equipotential lines? What is their relationship to electric fields lines? Directions of electric fields are indicated by arrows, why are no directions indicated on equipotential lines? Homework Equations The Attempt at a Solution
25. ### Why are electric field lines also referred to as "lines of force"?

Homework Statement Why are electric field lines also referred to as "lines of force"?
26. ### Static Electricity

What is it about the static electricity, I suppose on a molecular level, that is causing the interference with the experiment? Is it the like unlike charges of the charged objects and your clothes/body repelling one from another?
27. ### Coulomb's Law and Corrected Angle

The question should read: 1. How does the relationship between any "corrected angle and distance" demonstrate or relate to Coulomb's Law? 2. How does the relationship between any "angle and voltage-squared" demonstrate or relate to Coulomb's Law how?
28. ### Coulomb's Law and Corrected Angle

Hey sorry. It's my first time on this forum. I'm still not sure how to go back and edit what I wrote. I do think it's funny though that you commented on how what I wrote was difficult to read. "Please take some time thinking that is it possible for someone to understand what you wrote?"...
29. ### Static Electricity

Homework Statement How would static electricity on your clothes or on your body affect an experiment involving charged objects? Homework Equations Coulomb's Law The Attempt at a Solution The static electricity would attract the objects due to the like charges, assuming the objects...
30. ### Coulomb's Law and Corrected Angle

Homework Statement Corrected Angle, theta, vs Distance, r, demonstrate or relate to Coulomb's Law how? Homework Equations Coulomb's Law The Attempt at a Solution As the distance increases, the force decreases by a factor of 4 because "r" is squared in Coulomb's law. Homework...