Hmm, then let me try this again. I just want to find the moles of Lactose for now, then I think I got the rest.
1.06 g/mL * 1mol/342g * 12% lactose = 3.719x10^-4
Does that look right?
Thanks for the help btw.
Homework Statement
Lactose (C12H22O11; MM=342) is a sugar found in mamalian milk. The density of a 12.0% solution is approximately 1.06 g/mL. What is the molarity, molality, and mole fraction of the solution?
Homework Equations
M=g/L, m=mol/kg, molefraction=mol/mol??
The Attempt...
So if the normal boiling point is where the vapor pressure equals the external pressure, I can just set p2/p1 to 1.
So I have ln1=-25.179/8.314(1/210-1/T) then T equals the normal boiling point? Eh, I'm confused.
Homework Statement
Given the following data, determine the heat of vaporization and normal boiling point of ammonia
Temp (K):
200
210
220
230
235
Pressure (respectively)(torr):
65.3
134.3
255.7
456.0
597.0
Homework Equations
ln(p2/p1)=-deltaH/R(1/t2-1/t1)
The Attempt...
Homework Statement
20g of NH4NO3 (MM=80.05 g/mol) if dissolved in 125g of water in a coffee-cup colorimeter, the temperature falls from 23.5C to 13.4C. Determine 'q' for the dissolving of the compound. Is the process exothermic or endothermic?
Homework Equations...
So 0.2g KOH/56.1g/mol KOH = .003 mol and 0.002M HCL * 1.5L HCL = 0.003 mol.
So 0.003 mol KOH - 0.003 mol HCl =0, so the pH has to be 7, right?
But what if there was still some of a reagent left? Then you would need to calculate the volume of KOH, correct? And how would you do that when you...
Homework Statement
Calculate the volume of 0.108 M NaOH solution required to react completely with 145 mL of phosphoric acid solution that is 1.15x10^-2 M.
Homework Equations
n=MV
The Attempt at a Solution
NaOH \rightarrow Na^{+}+OH^{-}
H_{3}PO_{4} \rightarrow 3H^{+} + PO_{4}^{-}...
Homework Statement
Show that 1kg of CaF2 equals 13 mol.Homework Equations
Molar mass CaF2 = 78.074g/molThe Attempt at a Solution
I can take 78.074g/mol CaF2 * 13 mol = 1014.962 g CaF2
But I can't do this equation backwards, I'm missing a step. I would think if I'm converting g/mol to mol, I...
Thanks for the quick replies! You guys might be seeing me around here, I have to relearn all the calc and chemistry I've ever taken before next semester starts! :P
Appreciate your help!
Homework Statement
Cross vector A with vector B.
A = <0,3,4> B = <4,-4,7>
Homework Equations
a x b = (a2b3 - a3b2) i + (a3b1 - a1b3) j + (a1b2 - a2b1) k
(I think)
The Attempt at a Solution
AxB= i(21-16)-j(16-0)+k(0-12) = <5,-16,12>
I'm unsure if the component 'j' is correct...