Calculate Q (system) (J) and delta H (kJ/mol). Use data below and from methods: Mass of NaNO3 required (already calculated) = 8.5 grams Initial Temperature ti (0C) = 25.0 0C Temperature after 240 sectons (tf, final temp) = 19.0 0C Measuring the heat evolved or absorbed methods Weigh the calculated mass of NaNO3 needed to prepare 100mL of a 1.0M solution. Place 100mL of distilled water in the calorimeter and carefully add the solid NaNO3. Begin stirring and measure the temperature of the solution to the nearest 0.10C after 30seconds and every 30 seconds thereafter until the temperature attains either a maximum or minimum which is the final temperature tf. Calculate q(system), using specific heat=4.184J/g.0C, density ofsolution=1.0g/mL; heat capacity of calorimeter = 10J/0C Calculate the enthalpy change DH from q(system) and the number of moles NaNO3
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.
Calculate Q (system) (J) and delta H (kJ/mol).
Use data below and from methods:
-
Mass of NaNO3 required (already calculated) = 8.5 grams
-
Initial Temperature ti (0C) = 25.0 0C
- Temperature after 240 sectons (tf, final temp) = 19.0 0C
Measuring the heat evolved or absorbed methods
- Weigh the calculated mass of NaNO3 needed to prepare 100mL of a 1.0M solution.
- Place 100mL of distilled water in the calorimeter and carefully add the solid NaNO3.
- Begin stirring and measure the temperature of the solution to the nearest 0.10C after 30seconds and every 30 seconds thereafter until the temperature attains either a maximum or minimum which is the final temperature tf.
- Calculate q(system), using specific heat=4.184J/g.0C, density ofsolution=1.0g/mL; heat capacity of calorimeter = 10J/0C
- Calculate the enthalpy change DH from q(system) and the number of moles NaNO3
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