When HNO3 and Au are mixed together, what do you expect to happen, and why? No reaction, because Au is above H on the activity series and they cannot react
No reaction, because Au is lower on the activity series and cannot replace H
They form Au(NO3)2 and H2, because Au is more reactive and able to replace H
They form Au(NO3)2 and H2, because they trade places in a double replacement reaction

B

Explanation:

There can be no reaction because Au is above H on the activity series and cannot react.

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .

the answer is b & c i believe : )