ou want to heat the air in your house with natural gas ( CH4 ). Assume your house has 275 m2 of floor area and the ceilings are 2.5 m from the floor. Data for air: Cp (J/mol K) 29.1 Density (g/L) 1.22 Average molar mass (g/mol) 28.9 Calculate the mass of air (in grams) to be heated. Calculate the amount of heat (in megajoules) required to increase the temperature of this mass of air from 15°C to 22°C. If the energy density of CH4 is 55.5 MJ/kg, what is the mass of CH4 needed to heat your hou
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
You want to heat the air in your house with natural gas ( CH4 ). Assume your house has 275 m2 of floor area and the ceilings are 2.5 m from the floor.
Data for air:
| Cp (J/mol K) | 29.1 |
| Density (g/L) | 1.22 |
| Average molar mass (g/mol) | 28.9 |
Calculate the mass of air (in grams) to be heated.
Calculate the amount of heat (in megajoules) required to increase the temperature of this mass of air from 15°C to 22°C.
If the energy density of CH4 is 55.5 MJ/kg, what is the mass of CH4 needed to heat your house?
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