[neil.smif]

*delete me*!! I ve got another Chemistry problem.

I need to make up a 50% soln of hexadeconal in 50% dodecane

This is what I have- A solid powder of the hexadeconal, and a liquid dodecane      (the hexadeconal needs to be dissolved in a 50% solution of dodecane).

Am I right in thinking that if I add 10g of hexadeconal to 10ml dodecane,that would give me the 50:50 soln.

Thanks in advance!

[Borek]

More like 10 g + 10 g, unless you are specifically told to use %w/v.

I need to make up a 50% soln of hexadeconal in 50% dodecane

What I don't like about the question is this "50% in 50%" fragment. Sounds like you may be asked to first prepare 50% solution of dodecane (in what?), and than use it as a solvent to prepare 50% solution of hexadeconal.

[neil.smif]

If the dodecane was prepared in water, would the same principal apply,

I.e. 10ml dodecane in 10ml water, (vol 20ml) then dissolve 20g Hexadecanol in this solvent, is this right giving a 50:50 soln?

[Borek]

10 mL of dodecane + 10 ml of water is not 50% w/w, but around 43%. That's assuming dodecane dissolves in water. It doesn't.