Sciencemadness Discussion Board

Ksp -- Equilibrium Constant

pageleft - 5-11-2003 at 02:41

Im struggling here with a question.. ok so its pharmacy related but its all chemistry..

here goes.. i hope someone can help...

QUESTION :
In your pharmacy you have prepared 20mL of aqueous nose drops in which 50mg
methylhydroxybenzoate is dissolved as the preservative. The following data relates to
the solubility of methylhydroxybenzoate (molecular weight 200) at room temperature
and in boiling water: (you may assume that methylhydroxybenzoate does not form ions
when dissolved in water)

at 25°C the Solubility in water (g/L) 4.5
at 100°C the Solubility in water (g/L) 55


the pharmacy part needs Delta G calculations.. but thats not important.. i just want to know if there is a way to get the equilibrium constant (Ksp) from the values given? so is there?

Thanks for your help in advanced

unionised - 6-11-2003 at 15:30

I take it you that by Ksp mean a solubillity product. It's not defined for a single non- dissociated compound.