The moles of I2 that will form 38.58g of Ni3 is 0.147 moles
calculation
write the equation for reaction for formation of Ni3 from I2 and N2
that is 3I2 + N2 = 2NI3
find the moles of Ni3 formed = mass/molar mass
= 38.58g/ 394.71 g/mol = 0.098 moles
by use of mole ratio between I2 to NI3 which is 3 :2 the moles of I2
= 0.098 x3/2 = 0.147 moles
