4 NH3 + 302 2N2 + 6H₂O
2.) a) A chemist burned 0.25 moles of ammonia gas (NH,) in the presence of excess oxygen
pps to produce 2.95 grams of nitrogen gas (N2). Calculate the theoretical yield of
nitrogen gas.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.