Before 1962,dimes minted in the US contained the precious metal silver.A 2.08 gram dime is dissolved in nitric acid and reacted with saturated sodium chloride solution. This process precipitates all the silver in the dime as 342mg of AgCl(s). How many moles of silver did the dime contain?
To calculate the number of moles of silver in the dime, we need to follow these steps:
Step 1: Convert the mass of AgCl to moles of AgCl.
Given that the mass of AgCl precipitated is 342 mg, we need to convert it to grams by dividing it by 1,000:
342 mg รท 1,000 = 0.342 g
Next, we need to convert grams of AgCl to moles of AgCl by using the molar mass of AgCl. The molar mass of AgCl is calculated by summing the atomic masses of silver (Ag) and chlorine (Cl):
Ag: 1 x 107.87 g/mol = 107.87 g/mol
Cl: 1 x 35.45 g/mol = 35.45 g/mol
Molar Mass of AgCl = 107.87 g/mol + 35.45 g/mol = 143.32 g/mol
Now we can calculate the number of moles of AgCl:
Moles of AgCl = Mass of AgCl / Molar Mass of AgCl
Moles of AgCl = 0.342 g / 143.32 g/mol
Step 2: Convert moles of AgCl to moles of silver (Ag).
Since 1 mole of AgCl contains 1 mole of silver (Ag), the number of moles of AgCl is equal to the number of moles of Ag:
Moles of Ag = Moles of AgCl
Therefore, the number of moles of silver contained in the dime can be obtained by the calculations above.