Calculate δh∘ in kilojoules for the reaction of ammonia nh3 (δh∘f=−46.1kj/mol) with o2 to yield nitric oxide (no) (δh∘f=91.3 kj/mol) and h2o(g) (δh∘f=−241.8kj/mol), a step in the ostwald process for the commercial production of nitric acid.

4nh3(g)+5o2(g)→4no(g)+6h2o(g)

Which best describes the present-day universe? opaque, expanding very slowly, stars produce heavy elements transparent, expanding at an accelerated rate, stars produce heavy elements opaque, expanding at an accelerated rate, stars produce only hydrogen and helium transparent, expanding very slowly, stars produce only hydrogen and helium