Standard Molar Enthalpies of Combustion Substance Combustion Reaction Enthalpy of Combustion, AH: kJ at 25 °C) mol carbon C(s) + O2(8) → CO2(g) -393.5 hydrogen H,(g) + 0,(g) → H, O() -285.8 magnesium Mg(s) + 0,(3) → MgO(s) -601.6 sulfur S(s) + O2(g) → SO2(g) -296.8 carbon CO(g) + 0,(g) → CO,(g) -283.0 monoxide methane CH4(8) + 202(8) → CO2(8) + 2H2O(1) -890.8 acetylene C2H2(g)+ 02(8) –→ 2C0,(g) + H2O(1) -1301.1 C,H5OH(1) +30,(8) → 2CO,(g)+ 3H,O(I) ethanol -1366.8 methanol CH3 OH(1) + CO2(g) + 2H2O(1) -726.1 C3H18(1) + 02(3) –→ 8CO,(g) + 9H2O(!) isooctane -5461 Table 5.2

When 1.836 grams of sucrose (Molar mass 342.3 g/mol) is burned in a bomb calorimeter, the temperature of the calorimeter increases from 22.41°C to 26.63°C. If the heat capacity of the calorimeter is 4.900 kJ/°C, what is the heat of combustion of sucrose?

A 3.59°C increase in temperature occurs when a 0.232 g sample of benzoic acid (C7H6O2) is combusted in a bomb calorimeter. A 1.81 °C increase in temperature occurs when a 0.303 g sample of citric acid (C6H8O7) is combusted in the same bomb calorimeter. The heat of combustion of benzoic acid is -26.37 kJ/g. What is the molar heat of combustion of citric acid? Reminder: Any heats of combustion will be negative since these are exothermic reactions.

A gaseous fuel mixture contains 23.2% methane (CH4), 40.8% ethane (C₂H6) and the rest propane (C3H8) by volume. Part A When the fuel mixture contained in a 1.55 L tank, stored at 756 mmHg and 298 K, undergoes complete combustion, how much heat is emitted? (Assume that the water produced by the combustion is in the gaseous state.) Express your answer with the appropriate units. μA Value Units Review | Constants | Periodic Table ?

The flame in a torch used to cut metal is produced by burning acetylene (C2H2)(26.04 g/mol) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251 kJ of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 22.5  × 104 kJ of heat?                                            2 C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g) ΔH = –2502 kJ

When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 3.95 g of CuCl2(s) are dissolved in 108.60 g of water, the temperature of the solution increases from 23.05 to 26.27 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.86 J/°C. Based on the student's observation, calculate the enthalpy of dissolution of CuCl,(s) in kJ/mol. Assume the specific heat of the solution is equal to the specific heat of water. AHdissolution kJ/mol

A 44.0 g sample of unknown metal at 99.0°C was placed in a constant-pressure calorimeter containing 80.0 g of water at 24.0°C, the final temperature of the system was found to be 28.4°C. Calculate the specific heat of the metal.

Part A A silver block, initially at 55.8 °C, is submerged into 100.0 g of water at 24.1°C in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.3 °C. The specific heat capacities for water and silver are = 4.18 J/(g ·°C) and 0.235 J/(g·°C). What is the mass of the silver block? Express your answer to two significant figures and include the appropriate units. Cs, water • View Available Hint(s) Cs, silver = HA ? Value Units m =

Many barbeque grills use propane gas, C3H8(g) as a fuel source. Using standard enthalpies of formation, calculate the quantity of heat produced, in kJ, when 25 liters of liquid propane is completely combusted in air. (The density of liquid propane is 582 kg/m3.) Note: The propane is in the condensed liquid state in the tank but changes to the gas phase as it is released. Calculate the change in enthalpy for the reaction assuming all reactants and products are in the gas phase.

Consider the change in the internal energy of a system. what is the change in the internal energy, in joules, of a system that does 4.75 x 10^5 J of work, while 3.05 x 10^6J of heat is transferred into the system and 8.25 x 10^6J of heat is transferred from the system to the environment?