CSC290H5 Lecture Notes - Lecture 2: Joule, High Energy Stereoscopic System, Chemical Equation
Document Summary
A chemical equation may look like the following: ch4 + 2o2 co2 + 2h2o. Ch4(g) + 2o2(g) co2(g) + 2h2o(l), h = -890kj. But is not included within the definition of standard conditions. The above thermochemical equation tells us that when 1 mole of methane is burned completely in air to give co2 gas and liquid water, 890 kj of energy is released. A typical endothermic rxn: caco3(s) cao(s) + co2(g), h = +178 kj i. e. , we must supply 178 kj of energy to convert 1 mole caco3(s) to cao(s) & co2(g). Thermochemical equations describe the energy changes associated with 1 mole of something. e. g. , we saw above that the h for combustion of 1 mole ch4 at 298 k was 890 kj (or 890 kj/mole). When a thermochemical equation is multiplied by any factor, the value of h is also multiplied. Question: how much energy is released if we burn 1. 00 l ch4(g) at.
