If you perform an experiment where 5.183 grams HCl reacts completely with NaOH, what will be the heat flow that occurs? The ΔHrxn of HCl and NaOH neutralization is -56.0 kJ/mol. (Hint: put a negative sign on the answer to reflect heat transfer from the system to the surroundings; put no sign on the answer to reflect heat transfer from the surroundings to the system.)

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.