The mass of silver nitrate (agNO3) required to prepare 400g of 3.50% solution
=14 grams
calculation
mass % = mass of the solute/ mass of the solvent
let mass of the solute= y
mass of solvent= 400g
%mass= 3.50 % into fraction= 3.5/100
=3.5/100= y/400
multiply both side by 400
y= 14 grams