[scottydsntknow]

A metal   M   reacts with   phosphorus (  P4 )   to form a compound having the formula   M3P.
17.10 g   of the metal produce   21.61 g   of the compound. Calculate the molar mass of the metal.

i got the 4.51 g. of P4 and that is 4.51

the atomic number of P is 30.97

i just dnt know how or what to set up.
 do i do 4.51/123.88 that would give me .036 moles but i get lost

[Astrokel]

Start off with balanced equation and work with moles.

Read this by Borek: http://www.chembuddy.com/?left=balancing-stoichiometry&right=ratio-proportions