Balance the following reaction and use the equation to calculate the ΔHrxn. C3H8(g) + O2(g) → CO2(g) + H2O(g) Round your answer to the nearest whole number. ΔHrxn= kJ/mole

Ethanol (c2h5oh) is produced from the fermentation of sucrose in the presence of enzymes. c12h22o11(aq) + h2o(g) 4 c2h5oh(l) + 4 co2(g) determine the theoretical yield and the percent yields of ethanol if 680. g sucrose undergoes fermentation and 326.5 g ethanol is obtained. theoretical _ g _ percent %

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm

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.