## Finding out unknown compound in the solution and boiling point of the solution

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Dhamnekar Winod
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### Finding out unknown compound in the solution and boiling point of the solution

After a sample of compound X weighing 1.286 g was dissolved in 25 g of C6H6, the freezing point of the resulting solution was found to be 3.27℃.

What is the molecular weight of compound X? What is the name of solute compound? What is the boiling point of the solution?

Molecular weight of compound is 118 g. The boiling point of the solution is 81.255℃.

Are these answer correct? I don't know the name of the compound.
Last edited by Dhamnekar Winod on Thu Apr 22, 2021 7:54 am, edited 3 times in total.
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
ChenBeier
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### Re: Finding out unknown compound/element in the solution and boiling point of the solution

Dont think so, how you can dissolve tin in benzene?
Dhamnekar Winod
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Posts: 149
Joined: Sat Nov 21, 2020 10:14 am
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### Re: Finding out unknown compound/element in the solution and boiling point of the solution

I am wrong. I modified wrongly the original question given by authors. Now I corrected the question and answer. You may check it now.
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
ChenBeier
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### Re: Finding out unknown compound/element in the solution and boiling point of the solution

Dhamnekar Winod
Sr. Staff Member
Posts: 149
Joined: Sat Nov 21, 2020 10:14 am
Location: Mumbai[Bombay],Maharashtra State,India

### Re: Finding out unknown compound in the solution and boiling point of the solution

We know that 1.286 g of the compound are dissolved in 25 g benzene, and therefore in 1000 g of benzene, there are$$1.286 \times \frac{1000}{25}=51.44 g, \Delta T_{fp} = 5.50^\circ -3.27^\circ =2.23^\circ C; \Delta T_{fp} = K_{fp}\cdot m; m=\frac{\Delta T_{fp}}{K_{fp}}=\frac{2.23}{5.12}=0.436 m; \frac{51.44 g}{0.436 mol}= 118 g/mol$$

where,

$$\Delta T_{fp}=$$ change in temperature of the solution. m= molality of the solution.
$$K_{fp}=$$molal freezing point constant for benzene

What would be a name of the compound?
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
ChenBeier
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### Re: Finding out unknown compound in the solution and boiling point of the solution

Calculation is ok.
But without more information it is impossible to find out which compound it is.
Dhamnekar Winod
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Posts: 149
Joined: Sat Nov 21, 2020 10:14 am
Location: Mumbai[Bombay],Maharashtra State,India

### Re: Finding out unknown compound in the solution and boiling point of the solution

I think computed boiling point of the solution 81.255℃ is correct.
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
ChenBeier
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Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

### Re: Finding out unknown compound in the solution and boiling point of the solution

Yes its correct. But cannot say which compound it is. For this need more analysis, like NMR , IR, UV/ Vis spectra and elementar analysis of C, H, N,O, maybe Halogen.
As suggested it cannot be a metal like tin.