Chemistry

[Blue]

How many primary alcohols, which 3.7g releases 560 cm³ H₂ in reaction with Na, are there?

 

I tried to find Mr of alcohol, but I can't get the right solution.

Edited June 27, 2013 by Blue

[hypervalent_iodine]

I guess the first question is do you know what the overall reaction is?

[Blue]

Yes, I've just solved it, thank you anyway. But, I need help with another problem:

What is the volume of H2 (normal conditions) which gets released when we add 4.6g of elementary Na into 100g of pure ethanol?

[hypervalent_iodine]

If you got the first question, then this one should be pretty straight forward. What part of it are you struggling with?

[Blue]

I tried to convert everything into moles, but I don't get the right result, I'm a bit confused about the way I should use m(Na) ?

[hypervalent_iodine]

If you show me your calculations I can tell you where you might have a problem.

[Blue]

2 CH₃-CH₂-OH + 2 Na = 2 CH₃-CH₂-ONa + H₂

 

m( C₂H₅OH) =100g

Mr(C₂H₅OH)=46g/mol

 

n=m/Mr = 100/46=2.17mol

 

2mol:1mol=2.17:x

x=2.17/2=1.08mol H₂ but, this is not right, and don't know how to use m(Na)

 

V(H₂)= Vm*n=22.4* number of moles of H₂

 

 

I don't know how to find n(H₂)

[hypervalent_iodine]

Are you familiar with the concept of limiting reagents at all?

[Blue]

Yes, but I didn't have Chemistry classes for a year, so I can't remember many things. Thank you anyway

I solved it

[hypervalent_iodine]

No problems. Glad you solved it.