When a 2.5 mol of sugar(C11H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. If 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? Please show me all calculation.

Question

abb0t · Answer

z0mg fan + medal?! U promis?!

arihangdu · Answer

Help me please

arihangdu · Answer

Yes those who help will get

cuanchi · Answer

That is extortion!!!

cuanchi · Answer

delta T= k x molality

the change in temperature is proportional at a k (constant) that depends of the nature of the solvent and the molality (concentration of the solute in the solution as moles of solute per kg of solvent. 

the sugar is producing one unit per mole when put it in water, but the aluminum nitrate 4 units per mole. Then the active molality of the aluminum nitrate will be 4 times higher than the sugar.

arihangdu · Answer

Help please

arihangdu · Answer

Help on doing maths please

aaronq · Answer

Have you tried setting up the problem?

the formula is $\sf \Delta T=molality*K_b$

where Kb is the boiling point elevation constant (for water)

So first find the molality of the solution, the definition of molality is 

$\sf molality=\dfrac{moles~of~solute}{Kg~of ~solvent }$

arihangdu · Answer

2.5 mole/2 kg solvents = 1.25 kg of solvent water.
Al(NO3).   ---->  3NO3 + Al^3+ 
We have 3 mol of Nitate and 1 mol of Al. Is this correct my friends?

arihangdu · Answer

2.5 mole/2 kg solvents = 1.25 kg of solvent water.
Al(NO3).   ---->  3NO3 + Al^3+ 
We have 3 mol of Nitate and 1 mol of Al. Is this correct my friends?

arihangdu · Answer

I stuck in this question its too hard for me please help me,,,!,

cuanchi · Answer

Yes that is correct. Then the Kb is the same for both conditions, the difference is the molality, you can said
 Delta T1/ molality 1 = Delta T2 / molality 2

Delta T2 = Delta T1 x molality 2 / molality 1
1 can be the sugar an 2 can be th aluminium nitrate 

The problem doesn't mention the mass of water (we don't know if it is one kilogram or any other mass) but doesn't matter because both, the sugar an the nitrate are dissolved in the same mass. The only important thing is that sugar doesn't dissociate in water so is producing one particle an the aluminium nitrate 4 particles. In place of molality we can use directly the amount of moles.. In the sugar solution we will have 2.5 mol an in the ammonium nitrate 2.5 x 4 = 10

Delta T2= 1 x 10 / 2.5 = 4 C  !!!!!

Easy as 1 x 4 = 4  that's all Folks

arihangdu · Answer

Thank you very much.i appreciate your help.