If 16.9 kJ are released when 1.50 g of O2 reacts with an excess of NO, complete the thermochemical equation below.

Question

4 NO(g) + 3 O2(g) 2 N2O5(g)
ÄHrxn=???

Answer 1

Wouldn't that be 16.9 kJ x (32/1.5) x 3 = ??

Answer 2

I worked the problem out and got 1081.6. I need the least number of significant digits..so how would i round it?