Malika is creating a science fair experiment to demonstrate the Law of Conservation of Mass. First, she will find the mass of a sample of aluminum and a sample of oxygen. Then, she will combine the two samples and measure the mass of the product. Should Malika combine the reactants in an open or closed system in order to demonstrate the Law of Conservation of Mass?

Calculate the standard enthalpy of formation of liquid methanol, ch3oh(l), using the following information: c(graphite) + o2 latex: \longrightarrow ⟶ co2(g) latex: \delta δ h° = –393.5 kj/mol h2(g) + o2 latex: \longrightarrow ⟶ h2o(l) latex: \delta δ h° = –285.8 kj/mol ch3oh(l) + o2(g) latex: \longrightarrow ⟶ co2(g) + 2h2o(l) latex: \delta δ h° = –726.4 kj/mol