Silver chloride is simply AgCl while silver is Ag so we see that there is one mole to one mole correspondence. First calculate the moles of Ag:
moles Ag = 5.8 g / ( 107.87 g/mol)
moles Ag = 0.0538 mol
Then the mass of AgCl required:
mass AgCl = 0.0538 mol * 143.32 g/mol
mass AgCl = 7.71 grams