[wally7]

what ration do i use to make 48wt% HF to 3wt% HF? Please help.. much appreciated if you can.

[Arkcon]

Can you try to figure it out, so that you'll be able to make any ratio, of anything, from any starting point?  For example, if you had 100 % ethanol, do you know how to make 50 %?  Likewise, if you have 20 % NaCl, can you figure out how to get 10%, 5%, 2.5%, and use that knowledge to figure out the pattern?  Oh, and by the way, if you have 48% hydrofluoric acid, and need to dilute it, I hope you're doing it ... carefully.

[AWK]

You need density, at least of 48 % acid (will be close to 1.17) For 3 % solution you can yse density of water.

[ARGOS++]

[Arkcon]

Like ARGOS⁺⁺: says, we don't know if these concentrations are weight/weight or weight/volume, I was guessing we might not need density for weight/volume.  AWK: also assumes the starting and ending solutions are HF in water, which might not be true -- a very weak solution of HF is used in some cleaning agents, or as a slimy paste applied to automobile tires to shine them, and the density of this stuff could be anywhere.  Although my advice still holds, wally:, be carefull mixing this stuff.

[AWK]

Both, ARGOS++ and Arcton are right, but question should be more precised. When I think about liquids, as an undefined ratio I assume the volume ratio not the mass ratio (and then densities are needed)

[Fleaker]

I'd assume that if he's asking us how to dilute it, he's probably not really actually doing it in reality and this is just a homework problem.

Adding HF to water isn't exothermic in my experience for concentrations up to 70%, anymore than that and enough heat is evolved to offgas HF.

If, for some sick reason, he is using 48% HF, make sure that calcium gluconate past is available along with Viton gloves. Nitrile do NOT work well (take my word).

Akron's advice still holds.