During the combustion of methane (CH4), one mole of methane gas combines with two moles of oxygen gas (O2) to produce one mole of carbon dioxide gas (CO2) and two moles of water vapor. Which of the following chemical equations correctly represents the combustion of methane described above? a)CH4(g) + 2O(g) ↔ CO2(g) + 2H2O(g)
b)CH4(g) + 2O(g) ↔ CO(g) + 2H2O(l)
c)CH4(g) + 2O2(g) ↔ CO2(g) + 2H2O(g)
d)CH4(g) + 2O2(g) ↔ CO(g) + 2H2O(l)

The diagram shows the structures of horse and cat forelimbs. what does the diagram suggest about the evolutionary relationship between these two mammals? a. they have homologous structures, indicating a common ancestor. b. they have analogous structures, indicating a common ancestor. c. they have homologous structures, indicating that they do not have a common ancestor. d. they have analogous structures, indicating that they do not have a common ancestor.

What will most likely happen when two bromine atoms bond together?

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?