What is the theoretical yield of silver chloride?

AgNO3 (aq) + NaCl (aq) = AgCl (s) + NaNO3

MWt AgNO3 = 169.87; AgCl = 143.32

From the eqn 169.87 g of AgNO3 yield 143.32 g of AgCl

1.000g of AgNO3 yield 143.32/169.87 g of AgCl

Hence 4.27 g will yield (143.32/169.87) * 4.27 g of AgCl

= 3.60 g of AgCl which is the theoretical yield.

% yield = (2.56/3.60) * 100 = 71.1%

A skilled chemist (e. g., Marie Curie) would get close to 100%.