145.30g zn(no3)2 = moles of ZN(NO3)2

Answer 1

molar/formula mass of Zn(NO₃)₂ = 189.46 (you get this by adding up all the atomic masses)

145.30 g x 1 mol/189.46 g = 0.76692 moles Zn(NO₃)₂