Which is not true for combustion reactions? a. they produce carbon dioxide and water
b. a candle burning
c. they always occur in the presence of oxygen
d. they usually require a lot of energy to form products

Equal numbers of moles of he(g), ar(g), and ne(g) are placed in a glass vessel at room temperature. if the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressures of the gases remaining in the vessel after some of the gas mixture has effused?