How do I make up a 50mM solution of spermine tetrahydrochloride?

I need to know how much spermine tetrahydrochloride and H2O to use to make up a 50mM solution. The molecular weight of spermine tetrahydrochloride is 348.2g and I would like to make up 20ml. Can you explain how to do this please?





Thanks.How do I make up a 50mM solution of spermine tetrahydrochloride?
50mM = .05M


20ml = .02l





.05M means you have .05 moles of spermine tetrahydrochloride in each liter of solution. You need .02l solution, so the moles of spermine tetrahydrochloride you need is:


.05M x .02l = .001 mol





The mass of spermine tetrahydrochloride you need:


.001 mol x 348.2g/mol = .3482g





So you need to add .3482g spermine tetrahydrochloride in to 20ml of water.