Number of moles CuCl₂ :
mass solute / molar mass
31.0 / 134.4520 => 0.230 moles of CuCl₂
Mole ratio :
CuCl₂ + 2 NaNO₃ = 2 NaCl + Cu(NO₃)₂
1 mole CuCl₂ -------- 2 moles NaCl
0.230 moles -------- ? moles NaCl
moles NaCl = 0.230 x 2 / 1
moles NaCl = 0.46 / 1
= 0.46 moles of NaCl ( molar mass 58.44 g/mol )
Mass of NaCl:
1 mole ---------- 58.44 g
0.46 moles ----- ( mass of NaCl in theory )
mass of NaCl = 0.46 x 58.44 / 1
mass of NaCl = 26.8824 / 1
= 26.8824 g of NaCl
yield of NaCl :
NaCl produce / NaCl in theory x 100 %
( 21.2 / 26.8824 ) x 100
( 0.788 ) x 100 => 78.8 %
hope this helps!
