The condensed formula would be CH3-CH(CH4)-CH2-CH(CH4)-CH2-CH(CH4)-CH3. The molecular formula would be C10H25.
I think the correct answer would be the last option. The ocean zone which has the lowest water pressure would be the uppermost zone which is the Epipelagic zone. This zone is also called as the euphotic zone or the sunlit zone. It is the region which receives the most sunlight in order to allow photosynthesis.
The reaction, 2 C4H10 (g) + 13 O2 (g) = 8 CO2 (g) + 5 H2O (g), is the combustion of butane. A combustion reaction involves the reaction of a hydrocarbon with oxygen producing carbon dioxide and water. This reaction is exothermic which means it releases energy in the form of heat. Therefore, as the reaction proceeds,a heat energy is being given off by the reaction. This happens because the total kinetic energy of the reactants is greater than the total kinetic energy of the products. So, the excess energy should be given off somewhere which in this case is released as heat.
Mixture......................