2. In the photographic process, silver bromide is dissolved by adding sodium thiosulfate.
AgBr(s) + 2Na2S2O3(aq) --> Na3Ag(S2O3)2(aq) + NaBr(aq)
If you want to dissolve 0.250 g of AgBr (molar mass = 187.8 g/mol), how many milliliters of 0.0138 M Na2S2O3 should you add?
2006-09-29 06:58:36 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
1. convert the mass of AgBr into moles, say you get x.
2. from the equation above 1 mole AgBr requires 2 mols Na2S2O3. Soy you need 2x moles of Na2S2O3.
3. Calculate how many grams of Na2S2O3 is 2x moles of Na2S2O3, say z.
4. Calculate homw many grams of Na2S2O3 you have in 1 ml of 0.0138 M Na2S2O3, say y.
5. z divided by y is how much ml of the stuff you need to add.
2006-09-29 07:17:25 · answer #1 · answered by Dr. J. 6 · 0⤊ 0⤋
0.250 g of AgBr needs Na2S2O3 = 0.250*2/187.8 mol = 0.0027 mol
Thus vol reqd. = 0.0027/0.0138 = 0.2 ml
2006-09-29 07:12:47 · answer #2 · answered by ag_iitkgp 7 · 0⤊ 0⤋
Uh, why not just read the back of the package? Seems they tell you how much water to add to make it happen
2006-09-29 07:01:40 · answer #3 · answered by Anonymous · 0⤊ 0⤋