D) Calculate the Standard Heat of Formation of ethanol liquid using the molar enthalpy of combustion of ethanol given above in part a and the following heats of formation: deltaH°f:
(CO2 (g)) = -393.52 kJ/mol and deltaH°f(H20 (g)) = -241.82 kJ/mol

part a is c2h5oh+3o2-->2co2+3h2o​

Determine the energy released per kilogram of fuel used. given mev per reaction, calculate energy in joules per kilogram of reactants. consider 1 mole of tritium plus 1 mole of deuterium to be a mole of “reactions” (total molar mass = 5 grams).

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

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.