a technician went to the laboratory to prepare a solution of 250.0 mL of calcium carbonate (Na2CO3). It was weighed on the analytical balance 1.3316g of the solid calcium carbonate reagent. Knowing that salt has 99.5 %m/m, calculate the %m/v of this solution
You need to clear up a couple of problems. Do you mean CaCO3 or Na2CO3?
BTW, CaCO3 has limited solubility and I doubt you can dissolve 1.33 g CaCO3 in 250 mL of water. Second question is I don't get the 99.5% m/m. Where does that come from.