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, 201312 yr by Blue

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

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?

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

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) ?

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

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)

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

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

I solved it

No problems. Glad you solved it.