In: Chemistry
2. A silver recovery unit can process 1500 L of photographic silver waste solution per day. Adding excess solid sodium chloride to a 500 mL sample of the waste gives a white precipitate that, after filtration and drying, consists of 3.73 g of AgCl.
Write the balance ionic equation for the reaction between NaCl and Ag+1 ions.
What mass of NaCl must be added to the 1500 L of silver waste to ensure that all the Ag+ ions precipitate?
How many grams of Ag recovered from 1500 L waste?
Ag+1 + NaCl ------> AgCl + Na+
58.44 NaCl -------->143.32g AgCl
Density of Ag+1 ----> 10.49 g/cm3 , = 10490 g/L
Density of NaCl ---------> 2.165 g/cm3 = 2165 g/L
Total mass of Ag+1 -----> 10490 X 1500 = 15735000 g
Let x amount of solid sodium chloride is added to a 500 mL sample of the waste forms ----> 3.73 g of AgCl.
in 500 mL waste ..... contain 5245 g Ag+1
5245 g Ag waste reacts to give 3.73 g AgCl
1500 L Ag+1 = 15735000 g Ag+1 ions give ------------> 11190 g AgCl
grams of Ag recovered from 1500 L waste ------> 11190 g AgCl
143.32g AgCl is formed from 58.44 NaCl
To form 11190 g AgCl amount of NaCl needed = ((58.44/143.32)X11190) = 4562.82 g
mass of NaCl must be added to the 1500 L of silver waste to ensure that all the Ag+ ions precipitate = 4562.82 g