What mass of anhydrous salt is required to prepare a #50*g# mass of #"acetic acid trihydrate"#, #H_3C-CO_2H*3H_2O#?

1 Answer
May 5, 2017

Answer:

You want approx. #30*g# of the anhydrous salt.

Explanation:

Sodium acetate trihydrate has a formula mass of #136.04*g*mol^-1#.

And thus a #50*g# mass is a molar quantity of..........

#(50*cancelg)/(136.04*cancelg*mol^-1)=0.368*1/(1/(mol))=0.368*mol.#

Now this is #0.368*mol# with respect to sodium and acetate ions, but #1.10*mol# with respect to water.

And so we use the given molar quantity to calculate an equivalent mass of the ANHYDROUS salt:

#0.368*cancel(mol)xx82.03*g*cancel(mol^-1)=30.2*g#