Question

Approximately 46.4 g of sodium acetate (82.0 g/mol) will dissolve in 100 grams of water at 20 degrees Celcius. If 2.75 mol NaCH₃COO is dissolved in 355 g of water, the solution is:

A. dilute

B. concentrated

C. saturated

D. supersaturated

Answer 1

molar mass of CH3COONa( Sodium acetate)= 82 g/mole, moles of sodium acetate= 2.75

mass of sodium acetate= moles* molar mass= 2.75*82=225.5 gm

this is dissolved in 355 gm of water. concentration of solution = 225.5 gm of sodium acetate /355 gm =0.635 gm of sodium acetate/ gm of water

but actually 46.4 gm of sodium acetate can dissolve in 100 gm of water. hence at 20 deg,c, 46.6/100=0.464 gm of sdouum acetate/ gm of water can dissolve.

the prepared solution is nore than the limit of solubilty at 20 deg.c, the solution is supersaturated. D is correct.