What is the mass, in mg\text{mg}mg, of nitrogen gas (N2\text{N}_2N2) formed when 2.5 × 10-4 mol of ammonia (NH3\text{NH}_3NH3) reacts completely with an excess of copper(II) oxide?
3CuO(s)+2NH3(g)→3Cu(s)+N2(g)+3H2O(l) 3\text{CuO}(\text{s}) + 2\text{NH}_3(\text{g}) \rightarrow 3\text{Cu}(\text{s}) + \text{N}_2(\text{g}) + 3\text{H}_2\text{O}(\text{l}) 3CuO(s)+2NH3(g)→3Cu(s)+N2(g)+3H2O(l)3.5×10−33.5 \times 10^{-3}3.5×10−3
1.75×1001.75 \times 10^01.75×100
3.5×1003.5 \times 10^03.5×100
7.0×1007.0 \times 10^07.0×100