When methanol, CH, OH, is burned in the presence of oxygen gas, O2, a large amount of heat energy is released. For this reason, it is often used as a fuel in high performance racing cars. The combustion of methanol has the balanced, thermochemical equation CH, OH(g) + O,(g) → CO,(g) + 2 H,O(1) AH = –764 kJ %3D How much methanol, in grams, must be burned to produce 845 kJ of heat? mass:

A generic solid, X, has a molar mass of 61.8 g/mol. In a constant-pressure calorimeter, 18.6 g of X is dissolved in 369 g of water at 23.00°C. X(s) X(aq) The temperature of the resulting solution rises to 24.30 °C. Assume the solution has the same specific heat as water, 4.184 J/(g.°C), and that there is negligible heat loss to the surroundings. How much heat was absorbed by the solution? 2.01 kJ Incorrect What is the enthalpy of the reaction? AHTan= 6.67 kJ/mol Incorrect

1.) The internal energy of a system increases 253 J , while the system loses 93 J of heat. Determine the sign and the magnitude of work involved in this change. Show units!   2.) Consider the following thermochemical equation: Fe2O3 (s) + 2 Al (s) --> 2 Fe (s) + Al2O3 (s)   ∆H = –1704 kJ Determine the heat evolved, in kJ, when 23.3 g Al is consumed in this reaction. Show units!   3.) Calculate the heat needed, in joules, to raise the temperature of 32 g iron, Fe, from 25oC to 93oC. (specific heat capacity of iron is 0.450 J/goC). Show units.

Use the following information to determine the enthalpy for the reaction shown below. CS2() + 302(g) → CO2(g) + 2SO2(g) C(graphite) + O2(g) CO2(g) S(s) + O2(g) SO2(g) C(graphite) + 2S(s) CS2() AH = -393.5 kJ AH =-296.8 kJ AH = 87.9 kJ Select one: a. -899.2 kJ b. +1075.0 kJ C. -778.2 kJ d. -1075.0 kJ e. +778.2 kJ