Determine the mass of CO2 produced by burning enough of propane to produce 1.00×102kJ of heat. C3H8(g)+5O2(g)→3CO2(g)+4H2O(g)ΔH∘rx n=−2043kJ
Express your answer using three significant figures.

Determine the mass of CO2 produced by burning enough of octane to produce 1.00×102kJ of heat.
C8H18(l)+25/2O2(g)→8CO2(g)+9H2O(g)Δ H∘rxn=−5074.1kJ
Express your answer using three significant figures.

Which feature do highland climates have that lower elevation areas do not?

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.

Fossil fuels are organic compounds that are made from