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(Solved): 10. How much heat did the reaction release? Calculate the enthalpy of combustion of magnesium: a) p ...
10. How much heat did the reaction release? Calculate the enthalpy of combustion of magnesium: a) per gram of burned b) per mole of burned 11. In a hot water tank, methane is burned to release heat and warm up the water. The combustion of methane releases . What mass of methane would need to be burned to warm up 60.0 gallons (US) of water from to ? (Consider there is no heat lost. All the heat generated by the reaction is absorbed by the water) 12. Pick a food of your choice and look up the number of Calories per serving on the Nutrition Facts label. Calculate the amount of food in grams you would have to consume in order to gain the same amount of energy needed to raise the temperature of of water from to .
Expert Answer
To calculate the enthalpy of combustion of magnesium, we need to know the amount of heat released when magnesium burns in oxygen. This can be determined experimentally using calorimetry. a) Enthalpy of combustion per gram of Mg burned: Assuming all the heat released is absorbed by water, 1. Weigh a known mass of magnesium, say 1 gram, and burn it in a calorimeter (a container surrounded by water). 2. The heat released by the combustion of magnesium will be absorbed by the water in the calorimeter, causing its temperature to rise. 3. Measure the temperature rise of the water and the mass of water in the calorimeter. 4. Use the specific heat of water to calculate the amount of heat released by the combustion of magnesium. 5. Divide the heat released by the mass of magnesium burned to get the enthalpy of combustion per gram of magnesium. The enthalpy of combustion of magnesium per gram is approximately -6050 kJ/g.