Sunday

April 20, 2014

April 20, 2014

Number of results: 124,516

**Chemistry**

delta T = 101-100 = ?? delta T = Kb*molality Solve for molality. Now use the molality in the freezing point equation. delta T = Kf*m You have Kf and m, solve for delta T and convert to freezing point knowing the normal freezing point is zero C.
*Thursday, April 21, 2011 at 10:40pm by DrBob222*

**chemistry**

The freezing point of a 0.010 m aqueous solution of a nonvolatile solute is ?0.072°C. What would you expect the normal boiling point of this same solution to be? have no clue, thanks for the thelp Freezing point depression= N*kf* molality you have freezing point depression, ...
*Tuesday, December 5, 2006 at 2:59pm by tyler*

**Chemistry**

a) The freezing point will decrease the most (compared to parts "b" and "c". If the molality of the solute is m, the lowering of the freezing point will be deltaT = 2•Kf•m (the effective molality is 2m) b) The lowering of the freezing point will be deltaT = Kf•m (compare this ...
*Tuesday, June 23, 2009 at 4:24pm by GK*

**chem(freezing point)**

please help! I am lost! Question: Find the expected freezing point of a water solution that contains 286g of aluminum nitrate (Al(NO3)3) in 8.5 kg of water. answer in celcius Note the correct spelling of Celsius. delta T = i*Kf*m Determine the molality of 286 g Al(NO3)3 in 8.5...
*Tuesday, May 29, 2007 at 9:53pm by Anonymous*

**Chemistry**

moles = grams/molar mass Solve for moles. molality = moles/kg solvent Solve for molality delta T = Kf*molality Solve for delta T, then for the freezing point knowing the normal freezing point is zero C.
*Friday, January 14, 2011 at 4:24pm by DrBob222*

**chemistry**

1. normal freezing point - freezing point soln = change. 2. I think you want molality and not molarity. delta T = Kf*m. Solve for m = molality. 3. molality = moles/kg solvent Solve for moles. Then moles = grams/molar mass. Solve for molar mass.
*Monday, May 2, 2011 at 12:56am by DrBob222*

**chemistry**

moles = grams/molar mass. Solve for moles CaCl2. (You have a typo in the formula for CaCl2.) molality = moles/kg solvent. Solve for molality delta T = iKf*molality Solve for delta T; i = 3 Convert delta T to freezing point remembering the normal freezing point for water is 0 ...
*Monday, April 25, 2011 at 1:06am by DrBob222*

**Chemistry**

Use the density and PV = nRT to solve for molar mass of X. Then 3.46g X/molar mass X = moles. molality = moles/kg solvent delta T = Kf*molality normal freezing point - delta T = new freezing point.
*Tuesday, November 8, 2011 at 9:09am by DrBob222*

**chemistry**

a solution is prepared by mixing 2.17g of an unknown non-electrolyte with 225.0g of chloroform. The freezing point of the resulting solution is -64.2 C . The freezing point of pure chloroform is -63.5 C and its kf= 4.68C m^-1 . What is the molecular mass of the unknown? i know...
*Monday, February 10, 2014 at 11:16pm by hershi*

**chemistry**

delta T = Kb*m m = 18/62 = 0.29 mols molality = 0.29/0.15 = 1.93 m delta T = 1.86 x 1.93 = 3.6 degrees. The normal freezing point is zero, so the new freezing point must be 0.0 - 3.6 = -3.6. I suspect that's your problem. You are stopping at delta T which IS 3.6 but the ...
*Monday, April 7, 2008 at 12:24pm by DrBob222*

**Chemistry**

Colligative Properties The freezing point of distilled water was determined by recording a thermogram: -0.176. The freezing point of a 0.200 m (molality) solution containing an unknown, ionic compound was determined by recording a second thermogram. a. Determine the freezing ...
*Tuesday, January 28, 2014 at 12:56am by Sam*

**chemistry**

freezing point. delta T = Kf*molality. Convert 12.0 g glucose to moles. Moles = grams/molar mass. Then use m = moles/kg solvent to calculate molality, substitute that into the first equation to calculate delta T. Subtract from 0o to find the freezing point of the solution. ...
*Wednesday, February 10, 2010 at 11:50pm by DrBob222*

**Chemistry II**

If the freezing point depression (DTf) is 5.62 and the freezing point depression constant (Kf) is 3.90, what is the molality of the solution? Assume that the solute is a nonelectrolyte (i = 1).
*Tuesday, September 8, 2009 at 8:42pm by Lindsay*

**Chemistry**

What Occurs as a salt dissolves in water? the number of ions in the solution increases and the freezing point decrease the number of the ions in the solution increase and the freezing point increase the # of ions in the solution decrease and the freezing point increase the # ...
*Monday, March 26, 2007 at 10:28pm by Kat*

**Chem**

moles ethylene glycol = grams/molar mass. molality = moles/kg solvent. Solve for molality. delta T = Kf*m Find freezing point form delta T knowing that the normal freezing point of water is zero C. Same procedure for boiling point except delta T = Kb*m and add delta T to 100 C...
*Sunday, March 13, 2011 at 5:53pm by DrBob222*

**Chemistry**

Colligative Properties The freezing point of distilled water was determined by recording a thermogram: -0.176 degrees Celsius. The freezing point of a 0.200 m (molality) solution containing an unknown, ionic compound was determined by recording a second thermogram: -.904 ...
*Tuesday, January 28, 2014 at 5:59pm by Sam*

**Chemistry**

I am stuck in this problem I need to calculate the molality first so I could find T but I don't know which one is the solvent and which one is the solution the problem is to calculate the freezing point of a solution containing 12.2g of benzoic acid, dissolved in 250g of ...
*Monday, October 27, 2008 at 12:02am by Maria*

**Chemistry**

divide by the freezing point depression constant of water. freezing point=molality*freezing point depression constant
*Monday, May 3, 2010 at 12:47pm by bobpursley*

**Chemistry**

Five (5.00) grams of glucose, C6H12)6, is dissolved in 500.0 grams of acetic acid. What is the new freezing point and boiling point for the solution? Kf acetic acid = 3.90, Kb acetic acid = 3.07 (normal freezing point for acetic acid = 16.60 dg C, boiling point = 118.5 dg C) f...
*Thursday, August 9, 2007 at 7:39pm by lana*

**Chemistry**

convert g S to mols. (mols S/kg solvent) = molality delta T = Kf*molality delta T = Kb*molality I presume you have the constants for boiling point and freezing point for acetic acid.
*Thursday, February 7, 2008 at 9:31pm by drbob222*

**Chemistry**

This is a colligative property problem. Note that when an solute is dissolved in a solvent, the freezing point of the solvent decreases. This is called freezing depression, and the change in temperature can be calculated by (T,orig - T,new) = Kf * m where T,orig = original ...
*Sunday, November 10, 2013 at 12:28am by Jai*

**chemistry**

i need to know if I am in the right tract please let me know...I am calulating the molality of the following exercise so I could be able to apply the formula T=Kf * molality calculate the freezing point of a solution containin 12.2 grams of benzoic acid, dissolved in 250 grams...
*Monday, October 27, 2008 at 4:20pm by Joshua*

**chemistry**

which of the following would be expected to have the lowest freezing temperature? a. Ca(NO3)2 b. NaC2H3O2 c. CuSO4 d. HC2H3O2 e. C2H5OH per what? per gram? per mol? Any could have the lowest freezing point if I put a cup of any one and a scant amount of the others. For equal ...
*Saturday, April 21, 2007 at 8:28am by mary*

**AP Chemistry**

Why would .25 molality of CaCl2 have a larger effect on the freezing point of water than .25 molality of NaCl?
*Sunday, January 19, 2014 at 5:50pm by Diamond*

**CHEMISTRY..please help..thanks**

freezing. moles = grams/molar mass Substitute and solve for moles NaCl. molality = moles/kg solvent. Substitute and solve for molality. delta T = i*Kf*molality Substitute and solve for delta T and convert to freezing point. i for NaCl = 2. boiling point. You can use the ...
*Wednesday, November 10, 2010 at 10:45am by DrBob222*

**chemistry**

What is the expected freezing point of a 3.50 m (m standing for molality)aqueous solution of BaCl2(Kfp= 1.86 degrees Celsius/m)? What is the expected boiling point(Kbp= 0.512 degrees Celsius/m)? which is effected to the greater extent, the boiling point or freezing point? ...
*Sunday, April 7, 2013 at 9:29pm by Patricia*

**chemistry**

which solution has highest freezing point if all are at the same molality calcium chloride sodium nitrate potassium sulfate iron(III) nitrate all have same freezing point please explain
*Friday, March 16, 2012 at 2:51pm by kim*

**Chemistry!**

See above for a. b). delta T = Kb*molality. solve for molality. delta T = Kf*molality. solve for delta T. Subtract from 0o to find freezing point.
*Monday, April 26, 2010 at 5:51pm by DrBob222*

**A.P. CHEMISTRY**

delta T = Kb*molality 2.7 = 0.512*m solve for m molality = moles/kg solvent You have molality, kg = 0.250, solve for moles. moles = g/molar mass. solve for g. I don't think this is a good problem because the depression of freezing point and elevation of boiling point are based...
*Thursday, March 4, 2010 at 6:29pm by DrBob222*

**Chemistry.**

delta T = Kb*molality You know delta T, I assume you have Kb (the freezing point depression constant), calculate molality. Then molality = grams/kg solvent. You know molality and Kg solvent, calculate grams. From grams, use density to determine volume. Post your work if you ...
*Monday, November 23, 2009 at 3:06pm by DrBob222*

**Chem-Molality**

delta T = Kb*molality. Look up Kb for ethanol and solve for delta T. You know the normal boiling point of ethanol, simply add delta T to find the new boiling point. Same procedure for freezing point except you subtract delta T from 0 C to find the new freezing point. delta T...
*Sunday, April 17, 2011 at 5:45pm by DrBob222*

**chemistry**

molality = mols sugar/kg solvent Solve for molality delta T = Kf*m Solve for delta T and subtract from zero C to find the new freezing point.
*Wednesday, April 11, 2012 at 4:30pm by DrBob222*

**Chemistry**

What is the (a) molality, (b) freezing point, and (c) boiling point of a solution containing 2.29 g napthalene (C10H8) in 44.6 g of benzene (C6H6)?
*Friday, April 19, 2013 at 2:07pm by C*

**chemistry**

Freezing point depression= molality*Kf You know Kf for water, so compute the molality of the solution, molessolute/kg of water
*Wednesday, August 4, 2010 at 3:11am by bobpursley*

**chemistry**

If you are talking about the freezing point method there will be no effect. WHY? Because the reading of the normal freezing point is 1 degree too high and the reading for the freezing point of the solution containing the solute is alo 1 degree too high; however, the DIFFERENCE...
*Sunday, February 10, 2013 at 10:08pm by DrBob222*

**chem - freezing point**

moles ethylene glycol = grams/molar mass solve for moles ethylene glycol. molality = mols/kg solvent solve for molality delta T = Kf*m solve for delta T Subtract delta T from zero C to obtain the freezing point.
*Monday, October 4, 2010 at 2:19pm by DrBob222*

**Chem(again)**

What is the relationship between the amount of solute and the amount of freezing point depression? delta T = kf m where delta T is the difference between the normal freezing point and the f.p. with a solute, kf is the freezing point constant, and m is the molality. Some ...
*Tuesday, February 6, 2007 at 5:39pm by Chrissy*

**chemistry**

I assume you intended to ask "WHAT are the ideal.....". You have no amount of MgSO4 given; therefore, calculation of the boiling point and freezing point is not possible. If you wish it can be done this way. mols MgSO4 = grams/molar mass. Then molality = mols MgSO4/kg solvent...
*Wednesday, July 25, 2012 at 9:00am by DrBob222*

**Chemistry **

Delta tf is the CHANGE in freezing point. The initial freezing point was not 9C. Water freezes at 0C, and then when you add a solute, the freezing point is depressed some.
*Wednesday, February 3, 2010 at 10:25am by bobpursley*

**CHEMISTRY**

Assuming equal concentrations, rank these aqueous solutions by their freezing point: LiSO4, Li3PO4, SnCl4, NH4Br. (from highest freezing point to lowest freezing poinT) Thanks.
*Saturday, February 18, 2012 at 11:03pm by Kylie*

**chemistry**

Note the correct spelling of celsius. delta T = Kb*molality solve for molality 0.15 = 0.512*m and m = 0.15/0.512 Then substitute molality into the freezing point depression equation. delta T = Kf*m delta T = 1.86*(0.15/0.512) delta T = 0.5449 which rounds to 0.54 to two ...
*Tuesday, December 14, 2010 at 2:41pm by DrBob222*

**Chemistry**

I need this answered really fast. 4. Ethylene glycol (C2H6O2) is used as an antifreeze in cars. If 400 g of ethylene glycol is added to 4.00 kg of water, what is the molality? Calculate how much the freezing point of water will be lowered. The freezing-point depression ...
*Friday, May 17, 2013 at 4:45pm by Lauren*

**Chemistry: molality and freezing point?**

Silly meee!! This question is already answered. :)
*Tuesday, January 27, 2009 at 10:53pm by Agatha*

**chemistry**

Note the correct spelling of celsius. delta T = kf*molality Calculate delta T (then freezing point) knowing Kf and molality. molality = moles/kg solvent. You have kg solvent (but you will need to use the density) and moles = g/molar mass. For osmotic pressure, pi = MRT. don't ...
*Monday, February 8, 2010 at 9:53pm by DrBob222*

**Chemistry**

molality m= moles salt/kg of water freezing point depression = .52C * m
*Tuesday, January 15, 2008 at 9:33pm by bobpursley*

**chemistry...DRBobb i have a questionnnn**

Delta T is the difference between the normal freezing point and the freezing point of the solution. I wondered how you obtained a freezing point of 23 BUT I figured you had somehow managed it so 23 + 0.1 was the difference. If the freezing point of the solution before the ...
*Sunday, February 8, 2009 at 8:13pm by DrBob222*

**chemistry**

1.00 times 10^2 WHAT of H2O? mols NiSO4 = grams/molar mass. molality = m NiSO4 = mols/kg solvent. Tnen delta T = i*Kf*m i = 2 for NiSO4. You know Kf and m, solve for delta T. Finally, subtract delta T from the normal freezing point to find the new freezing point.
*Wednesday, January 9, 2013 at 12:36pm by DrBob222*

**chemistry**

lowest+freezing+point+of+Kbr+AlNO33+CH3COONa+NaNO2+MgCl2+of+same+molality
*Friday, March 29, 2013 at 9:39pm by deepak*

**Chemistry **

I believe you need to rethink this question. For example, in the freezing point depression, we have delta T = Kf* molality and molality = moles solute/kg solvent and moles solute = grams/molar mass. So I would think adding grams makes more moles and more moles increases ...
*Sunday, April 11, 2010 at 1:05am by DrBob222*

**chemistry**

delta T = Kb*molality molality = moles/kg solvent moles = g/molar mass [convert 22.8 g glucose to moles using equation 3. Convert moles glucose to molality using equation 2. Then calculate delta T using equation 1.] Then delta T = Kf*m for the freezing point section. The same ...
*Sunday, February 28, 2010 at 1:25pm by DrBob222*

**chemistry**

First you solve for I (vant hoff factor) in the freezing point eqn. You are provided molality, delta fp and can get the kf from a textbook (hint since its aqueous, use value for h2o). Next, take this I value and plug it into the boiling point eqn with the given molality and ...
*Tuesday, December 5, 2006 at 2:59pm by erin*

**chemistry**

First you solve for I (vant hoff factor) in the freezing point eqn. You are provided molality, delta fp and can get the kf from a textbook (hint since its aqueous, use value for h2o). Next, take this I value and plug it into the boiling point eqn with the given molality and ...
*Tuesday, December 5, 2006 at 2:59pm by erin*

**chemistry**

if the freezing point of the solution had been incorrectly determined to be lower than the true freezing point, how would that affect the calculated molar mass? Explain. The molecular weight would be higher if the true freezing point is bigger than the determined freezing ...
*Sunday, February 1, 2009 at 1:34am by Anonymous*

**chemistry**

Calculate the freezing point of 0.15 m calcium chloride aqueous solution. Assume that the molal freezing point depression constant of water is 1.86°C·kg/mol and that the freezing point of water is 0.00°C
*Thursday, April 19, 2012 at 2:39am by hereyago*

**CHEMISTRY- PLEASE HELP:)!**

Pure lauric acid is melted and the freezing point is determined to be 43 degrees celsius. A solution is made by dissolving .50 grams of paradicholrobenzene into 3.00 grams of lauric acid. Determine the molality of this solution. I got 1.1m. which is right. But then it says the...
*Wednesday, April 16, 2008 at 9:46pm by Miley*

**chemistry**

convert 12.0 g CCl4 to moles. moles = grams/molar mass molality = moles/kg solvent solve for molality delta T = Kf*m. Solve for delta T and subtract from the normal freezing point of benzene.
*Wednesday, April 28, 2010 at 10:08pm by DrBob222*

**Chem II**

Boiling point. delta T = i*Kb*m where i = number of particles Kb is boiling point constant m = molality. freezing point. delta T = i*Kf*m where Kf is freezing point constant. i and m have same meaning as above.
*Thursday, February 14, 2008 at 3:56pm by Anonymous*

**chemistry**

delta T = i*Kf*molality i = 1 for glucose i = 3 for BaCl2 i = 2 for NaCl i = 3 for Na2SO4 You CAN calculate each with the data given and arrange them from the answers OR you can look at i*m and see which is the largest. The largest value of i*m will have the lowest freezing ...
*Tuesday, March 8, 2011 at 8:39pm by DrBob222*

**Chemistry**

molality = moles/kg solvent Solve for molality. delta T = i*Kf*m Solve for delta T and subtract from the normal freezing point. i is the van't Hoff factor and is the number of dissolved particles. For example, for MgSO4 that will be two since MgSO4 dissociates into Mg^+2 and ...
*Thursday, April 29, 2010 at 5:30pm by DrBob222*

**chemistry**

When 18 g of ethylene glycol C2H6O2 is dissolved in 150 g of pure water, the freezing point of the solution is _C . (The freezing point depression constant for water is 1.86C kg) what i tried was 18/62 to find the moles. then i got .29/.150 to solve for the molality. then i ...
*Monday, April 7, 2008 at 12:24pm by david*

**Chemistry**

The freezing point of benzene is 5.5°C. What is the freezing point of a solution of 8.50 g of naphthalene (C10H8) in 425 g of benzene (Kf of benzene = 4.90°C/m)? I worked this problem for someone just a couple of days ago. delta T = kf m kf = 4.90 m = molality = mols/kg. ...
*Wednesday, January 24, 2007 at 2:47pm by Kelly*

**chemistry**

moles NaCl = grams/molar mass = ? Solve for moles. molality = mols/kg solvent Solve for molality freezing point: delta T = i*kf*m boiling point: delta T = i*Kb*m i = 2 in both cases. Technically we can't calculate molarity since no density is listed. 800 mL solvent is not the ...
*Monday, November 21, 2011 at 3:34pm by DrBob222*

**Chem help!!**

A rock salt (NaCl), ice, and water mixutre is used to make homemade ice cream. How many grams of rock salt must be added to lower the freezing point 10.0 degrees C? I have no idea what to do, please help! delta T = Kf*i*m delta T = 10. Kf is the molal freezing point constant, ...
*Thursday, May 3, 2007 at 7:24pm by Lindsay*

**chemistry**

moles = gram/molar mass calculate moles C4H10. molality = moles/kg solvent. calculate molality. delta T = Kf*m calculate delta T and from there freezing point.
*Sunday, March 7, 2010 at 5:28am by DrBob222*

**Chemistry**

Cyclohexane has a freezing point of 6.6 degree Celsius and a K(f) of 20.0 degree Celsius/m. 1.50g of an unknown solute is dissolved wth 18.0g of cyclohexane. The freezing point of the solution was 1.3 degree Celsius Using this iInformation assuming the solute doesn't ...
*Monday, May 27, 2013 at 9:08pm by Michael*

**Chemistry**

I did an experiment to determine the freezing point depression and then find the molecular weight of the unknown solute added to the solvent, what would be the effect on calculating the molecular weight if some cyclohexane(my solvent) evaporated while the freezing point of the...
*Wednesday, February 25, 2009 at 9:05am by Lauren*

**Chemestry**

delta T = Kf*molality Remember molality = #mols/kg solvent. After you find delta T, then subtract that from 7.7 to find the freezing point of the solution.
*Sunday, October 26, 2008 at 5:38pm by DrBob222*

**Chem**

moles ethylene clycol = grams/molar mass. Solve for mole. molality = moles/kg solvent Solve for molality delta T = Kf*m and convert to freezing point. delta T = Kb*m and add to 100 C to convert to boiling point.
*Tuesday, March 22, 2011 at 6:53pm by DrBob222*

**CHemistry....Please double check DrBobb**

Hey im not really sure, but i had posted it up before and someone helped me here, but i will try my best: The formula you'll need to use for this problem is: Freezing Point = Kf * m Start by calculating the Freezing Point: Freezing Point (-23.0)-(0.0) =-23.0 degrees C Next, ...
*Saturday, January 24, 2009 at 1:06pm by Saira*

**chemistry**

mols S8 = grams/molar mass Solve for mols. molality = m = mols/kg solvent Solve for m delta T = Kf*m Find delta T and subtract delta T from normal freezing point to find new freezing point. delta T = Kb*m Find delta T and add to normal boiling point to find new boiling point.
*Monday, April 15, 2013 at 11:45am by DrBob222*

**chemistry**

The freezing-point depression is -0.930 Celsius degree. Determine the molality of the solution of an unknown nonelectrolyte in water. Please help!! I do not understand this problem!
*Tuesday, February 7, 2012 at 5:28pm by vivian*

**Chem-Molality**

What are the boiling point and freezing point of a 0.22 m solution of sucrose in ethanol? Can someone help me with this quickly? I'm SO confused~!
*Sunday, April 17, 2011 at 5:45pm by Hai*

**CHEM please HELP**

delta T = Kf*molality delta T = 0.660 Look up Kf for benzene (the freezing point depression constant for benzene which probably is in your text). Calculate molality. Then Kg solvent x molality x molar mass = grams. Solve for molar mass.
*Friday, February 13, 2009 at 8:14pm by DrBob222*

**Chemistry**

The normal freezing point is zero C. Therefore, the new freezing point will be -5.86 degrees C. However, when I multiply 3 x 1.86 I obtain 5.58 and the freezing point would be -5.58.
*Tuesday, April 27, 2010 at 8:18pm by DrBob222*

**Chemistry **

delta T = i*Kf*m i = number of particles in the solution. Kf = freezing point constant. m = molality.
*Sunday, August 29, 2010 at 6:58pm by DrBob222*

**College Chemistry2**

Look up normal freezing point benzene. Look up freezing point constant for benzene (Kf = ?). delta T = Kf*molality Solve for molality. molality = moles/kg solvent Solve for moles moles = grams/molar mass Solve for molar mass. Find the mass of the empirical formula. (molar mass...
*Saturday, February 5, 2011 at 11:31pm by DrBob222*

**Chemistry**

Calculate the freezing point depression and osmotic pressure at 25 degrees C of an aqueous solution of 1.0 g/L of a protein (mol wt= 90,000) if the density of the solution is 1.0 g/mL. I know how to calculate freezing point depression and osmotic pressure, but I'm having ...
*Saturday, March 24, 2007 at 4:37pm by Jessica*

**chemistry**

moles FeCl3 = grams/molar mass Solve for moles. molality = #moles/kg solvent Solve for molality = m delta T = i*Kf*m i = 4 You know m, Kf, and i, solve for delta T and subtract from the normal freezing point of water.
*Friday, February 24, 2012 at 8:06pm by DrBob222*

**Chemistry**

The boiling point of an aqueous solution is 102.48 °C. What is the freezing point? I know that formula for freezing point is delta Tf = Kf*m but what do I plug in for each?
*Tuesday, January 29, 2013 at 9:22pm by Anon*

**physical chemisry**

moles sucrose = grams/molar mass. Solve for moles. molality = moles sucrose/kg solvent. Solve for molality. delta T = Kf*molality. solve for delta T and from there the freezing point.
*Tuesday, April 6, 2010 at 2:41pm by DrBob222*

**chemistry**

A 0.0230 g sample of an unknown was dissolved in 2.260 g of benzene. The molality of this solution, determined by freezing point depression, was 0.0408 m. What is the molecular weight of the unknow substance?
*Thursday, October 4, 2012 at 11:23pm by Crystal*

**chemistry**

10.0 g sample of p-dichlorobenzene, a component of mothballs, is dissolved in 80.0 g of benzene, C6H6. The freezing-point of the solution is 1.20oC. The freezing point of benzene is 5.48oC. The molal freezing –point constant, kf, for benzene is 5.12oC/m. Calculate the apparent...
*Thursday, August 6, 2009 at 12:24pm by Jim_R*

**chemistry, freezing point depression**

Hey guys I did a lab and I have to answer the questions relating to the lab. I did question 1 & 2, can someone check if they are correct, and question 3 I don't know how to do it. 1. Calculation to Determine the molecular weight of unknown substance Mass of unknown used: 2.0 g...
*Friday, February 6, 2009 at 3:36pm by Sev*

**Chemistry**

As the mixture reaches the freezing point, the solvent (in this case water?) freezes which makes the solution more concd in alcohol. A more concd solution means the freezing point is decreased. This continues which makes the freezing point a broad range instead of a sharp point.
*Wednesday, February 23, 2011 at 5:02pm by DrBob222*

**Chemistry**

If the freezing point of pure toluene is -95.15 oC and its freezing point depression constant is -8.38 oC/molal, what is the freezing point of a solution made by dissolving 39.338g of anthracene (C14H10) in 150.0mL of toluene? (Density of toluene = 0.8669g/mL)
*Wednesday, January 30, 2013 at 9:34pm by Jaden*

**molal**

the freezing point of ethanol (C2H5OH) is -114.6C. the molal freezing point depression constant for ethanol is 2.00C/m. what is the freezing point (C) of a solution prepared by dissolving 50.0 g of glycerin (C3H8O3, A nonelectrolyte) in 200 g of ethanol. i tried to solve it on...
*Thursday, September 16, 2010 at 4:33am by lisa*

**Chemistry problem**

What is the expected freezing point of a 3.50 m aqueous solution of BaCl2 (Kfp=1.86C/m)? What is the boiling point (Kbp=0.512C/m? & which is affected to the greater extent, the boiling point or the freezing point?
*Thursday, November 12, 2009 at 4:19pm by Dan*

**Chemistry**

calculate the freezing point of a solution containing 12.2 grams of benzoic acid, dissolved in 250 grams of nitrobenzene. the freezing point of nitrobenzene is 5.7 celsius and its freezing point depression constant is 7.0 celsius/m. please help
*Monday, October 27, 2008 at 8:50am by Joshua*

**chemistry**

What's the freezing point of benzene? delta T = i*Kf*molality i = 2 for NaCl. Kf = ?? for benzene. solve for molality. Then molality = moles/kg solvent. Convert 1 kg solvent (benzene) to moles. moles = grams/molar mass. Finally, mole fraction NaCl = moles NaCl/(moles NaCl + ...
*Sunday, December 5, 2010 at 5:15pm by DrBob222*

**Chemistry**

1. Which of the following is not true? a. The freezing point of sea water is lower than the freezing point of pure water. b. The boiling point of a water sample from the Salt Lake is lower than the boiling point of pure water. c. The freezing point of 0.1 M NaCl is lower than...
*Monday, March 17, 2008 at 12:48pm by Cameo*

**molal (again)**

i tried to solve it on my own but im confused about the last part, this i what i have so far.. moles of glycerin= 50.0/92.10=0.54 molality=0.54/0.200=2.7 is that right? im a little confused about the numbers im supposed to use for step 3... this was the question: the freezing ...
*Wednesday, September 15, 2010 at 7:55pm by lisa*

**Chemistry**

An aqueous solution of an unknown compound boils at 101.00 degrees Celsius (760 torr). What is the molality, and freezing point of this solution?
*Thursday, April 21, 2011 at 10:40pm by John*

**AP Chemistry**

Convert 18 fl oz to grams and to kg. 1 oz = 28.35 grams. molality = mols/kg solvent Solve for molality. Then delta T = Kf*m You know Kf and m, solve for delta T, then subtract from zero C to find the new freezing point.
*Sunday, February 10, 2013 at 11:09pm by DrBob222*

**Chemistry**

calculate the freezing and boiling points of each of the following solutions. (a) 0.37 m glucose in ethanol freezing point ______I got -1.2e2 but its wrong_______°C boiling point _________I got 1.1e2 but its wrong:(____°C (b) 15.0 g of decane, C10H22, in 37.9 g CHCl3 freezing ...
*Thursday, March 24, 2011 at 7:09pm by Rebekah*

**Chemistry **

So its deltaTf = Kf * m m= 9.70°C/-1.86°C kg/mole = 5.2515 m (molality) What i'm not sure about is, if Delta Tf= in this equain is tfinal-t initial or its the freezing point as ypu mentioned .5C
*Wednesday, February 3, 2010 at 10:25am by Saira*

**Chemistry**

a solution of 0.2113 g of water dissolv ed in 25g of a solvent freezes at 11.5 degrees celcius below the freezing point of the solvent. what is the Kf for the solvent? A)0.735 B)1.36 c)5.39 D)24.5 Help!!! delta T = Kf*molality Calculate molality = #mols solute/kg solvent, plug...
*Friday, April 27, 2007 at 2:48pm by natali*

**Chemistry**

delta T = Kf*m, then solve for freezing point knowing that 0C is the normal freezing point of an aqueous solution.
*Tuesday, January 18, 2011 at 12:39am by DrBob222*

**Chemistry**

ok so my freezing point for NaCl was -2.0 so I can do -2.0-(0.5)= -2.5 degrees celsius. My freezing point for DI water was positive 0.5. So delta T would be -2.5?
*Monday, February 20, 2012 at 4:23pm by Hannah*

**Chemistry**

Explain why the freezing point of a pure solvent is constant, whereas the freezing point of a solution decreases with steady cooling.
*Sunday, March 20, 2011 at 11:39pm by Cassie*

**chemistry freezing point **

What is freezing point depression when 125g of br2 is added to 755g of Benzene? Kf(benzen e = 5.12°C\m.
*Sunday, January 21, 2007 at 9:51pm by janee *

Pages: **1** | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Next>>