33. If 15.0 g of nitrogen reacts with
15.0 g of hydrogen, 10.5 g of
ammonia is produced. What is the
percent yield of this reaction?

what's the

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.