How is enthalpy used to predict whether a reaction is endothermic or exothermic?
are ch4 (g): hf = –74.6 kj/mol; co2 (g): hf = –393.5 kj/mol; and h2 o(g): hf = –241.82 kj/mol.
how much heat is released by the combustion of 2 mol of methane?

The sketch shows a rynchosaur, an extinct animal that is known only from fossils. there has been much debate about the classification of these creatures. some scientists suggest that they belong with primitive amphibians, and some think they are related to snakes and lizards.the data equally support both cases. which statement best explains how to draw a cladogram that includes the rynchosaur? draw the cladogram for amphibians. draw the cladogram for reptiles. draw two cladograms, both showing the traits, and leave it as a hypothesis. draw two cladograms, both showing the traits, and have scientists vote

Does all the energy stored by the phytoplankton reach the top level of the pyramid

Which of the following initial observations would more directly lead to this research study? a) ginko biloba is cost effective and also possesses heart-protective, antioxidant, anti-inflammatory properties. b) metformin is an effective treatment of patients with t2d, but shows side effects that complicate the disease state. c) over the past several years, the cost of treating t2d within the united states has increased dramatically. d) many plants contain molecules that improve the health and quality of life of patients with a variety of diseases like t2d. e) t2d affects millions of individuals in the usa and worldwide many of who could benefit from improved therapies.