How many of the zeros in the measurement 0.050060 are significant

3 of them are significant. Two are sandwiched by nonzero significant numbers and since there is a decimal in the number, the zero on the end is also significant

Since there is the same amount of agn03 in both silver chloride and silver nitrate they produce the same amount of moles. therefore silver chloride produces the same amount of silver nitrate, so your answer is 15.0 moles of silver nitrate. i hope this !