<span>Best Answer: Mn(ii) is catalyst
Stetep-1 is slow step
Steps-2,3 are fast steps
intermediates are Mn(iii)and Mn(iv)
since step -1 is slow rate depends on Ce(iv) and Mn(ii) only
not on Tl(i) as it is involved in fast step-3</span>
Look at the periodic table to find the charge on atoms. Magnesium is +2 and Nitrogen is -3. Since there are two nitrogen charge 2*-3 = -6 there needs to be 3 Mg then (3*2+ = 6+) to pair with the two nitrogen. 3 Mg(+2) + 2 N(-3) = Mg3N2