Hot water that is 78.0°C is to be mixed with 4L of cold water that is 23.0°C. What should be the amount of hot water for them to have a final temperature of 24°C?
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.
Hot water that is 78.0°C is to be mixed with 4L of cold water that is 23.0°C. What should be the amount of hot water for them to have a final temperature of 24°C?
When water at two different temperatures is mixed, the temperature of cold tap water increases and hot tap water decreases till the whole mixture gets same temperature.
Energy lost by the hot water which is at 78.0oC (exothermic) and energy gained by the cold water that is at 23.0oC is equal at thermal equilibrium (24.0oC).
Change in temperature is,
Density of water is 1000.0 g/mL. Thus, mass of cold water is,
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