he assumption made when chemical reactions are performed which allows u

Q: What is meant by the standard enthalpy of formation?

A: The difference in enthalpy during formation one mole of desired compound from its reactant elements…

Q: The thermite reaction can be written as 2Al(s)+Fe2O3(s)→2Fe(s)+Al2O3(s)                  ΔH∘=−850kJ…

A: Given: The value of  is -850 kJ. The amount of heat released in 314.5 kJ. Introduction: According to…

Q: H2(g) + F2(g) → 2 HF(g)    ΔH = -542 kJ What would be the enthalpy change for the reverse of the…

A: Since, The standard enthalpy of the formation is defined as change of enthalpy of 1 mol of the…

Q: b How much energy is evolved or absorbed as heat in the oxidation of 12.0 g of NH3? Heat of…

A: Enthalpy is a amount of heat evolved or absorbed for a chemical changes at constant pressure.

Q: .If a system does 84.0 kJ of work on its surroundings and releases 105 kJ of heat against a constant…

A: Given : Work done on surrounding by system = 84.0 KJ  And heat released = 105 KJ Since heat is being…

Q: Based on this value and the standard enthalpies of formation for the other substances, the standard…

A: Standard enthalpy of formation is the change in enthalpy that accompanies the formation of one mole…

Q: A scientist measures the standard enthalpy change for the following reaction to be -138.8 kJ : H2(g)…

A: The given reaction is as follows: H2(g)+C2H4(g) → C2H6(g) The standard enthalpy change for the…

Q: Write out the chemical reaction whose enthalpy is the heat of formation of gaseous methane, CH4.

A: Standard equation of formation is equation represents formation of one mole compound from its…

Q: A scientist measures the standard enthalpy change for the following reaction to be 2885.4 kJ:…

A: 6CO2 (g)  + 6 H2O (l)  ---> C6H12O6 (s) + 6 O2 (g)  ∆Hrxn  = 2885.4 KJ/mol ∆H°f H2O = ?

Q: A scientist measures the standard enthalpy change for the following reaction to be 223.4 kJ :…

A: Given that -  Enthalpy change of the following Reaction -  CaCO3(s) ---> CaO(s) + CO2(g) is =…

Q: If the reaction of 2.5 g of Ca transfers 487 J of heat to a solution in a calorimeter (i.e. qsoln =…

A: Given : Mass of Ca reacting = 2.5 g And amount of heat transferred to the solution = 487 J Atomic…

Q: The standard molar enthalpy of formation of NH3(g) is –45.9 kJ/mol. What is the enthalpy change if…

A: Given, The standard molar enthalpy of the formation of NH3(g) is given by= -45.9 kJ/mol The mass of…

Q: A scientist measures the standard enthalpy change for the following reaction to be -59.4 k) :…

A: Answer: Enthalpy of a reaction is always equation to the difference of enthalpy of formation of…

Q: Consider the following reaction: 2C6H6() + 15 O2(g)- 12 CO2(g) + 6 H20() AH = -5.869 x 103 kJ An…

A: Each reaction takes place account to their stoichiometric radio and account to those things the heat…

Q: A scientist measures the standard enthalpy change for the following reaction to be -577.0 kJ:…

A: We have given that  H2CO(g) +O2(g)  →  CO2(g)  + H2O(l)                                   ∆Hrxn =…

Q: Pentane (C5H12)(C5H12) is a component of gasoline that burns according to the following balanced…

A: We have C5H12(l)+8O2(g)→5CO2(g)+6H2O(g) The standard enthalpy of formation of liquid pentane is…

Q: ) Write an equation for the combustion of 1 mol of pentane gas, C5H12(g), to form carbon dioxide gas…

A:

Q: A scientist measures the standard enthalpy change for the following reaction to be 215.5 kJ : CH4(g)…

A:

Q: 2. To study the possible amount of energy generated by a person, the person can be roughly viewed as…

A:

Q: For the reaction H,(2) + 0,) → H,0M AH = - 286KJ/mol Calculate the enthalpy change when 2.50 g of…

A:

Q: What is enthalpy change for a reaction and how does this differ from the experimental heat flow…

A: Definition~ Enthalpy is the measurement of energy in a thermodynamic system. The quantity of…

Q: A chemist measures the energy change AH during the following reactic 2 Fe,03(s) → 4 FeO(s)+O½(g)…

A: if ∆H is positive it means heat is absorbed then the reaction will be endothermic.

Q: 1. Calculate the enthalpy of reaction for the combustion of methane gas, CH4, to form CO,(g) +…

A: In this question, we want to Calculate tye Enthalpy of the combustion Reaction for methane. You can…

Q: Determine the enthalpy (in kJ/mol) for the reaction 3 SiCl₄ (s) + 4 Fe (s) → 4 FeCl₃ (s) + 3 Si (s)…

A: To solve this we have to do some  mathematical operations with the given  two equations to get the…

Q: A scientist measures the standard enthalpy change for the following reaction to be 154.8 kJ :…

A:

Q: What is enthalpy, and what is ΔH for a reaction, and what does it mean if ΔH is positive or…

A: Enthalpy can be defined as the total amount of heat of the system which can be represented by a…

Q: 2NO(g) + 02(g)–2NO2(g) Based on this value and the standard enthalpies of formation for the other…

A: Given  2NO (g) + O2 (g) ---> 2 NO2 (g)  ∆H rxn = -112.0 KJ  ∆H°f (NO2) = ?

Q: A system absorbs 1.66E2 kJ of heat and the surroundings do 1.032E2 kJ of work on the system. What is…

A: We have to predict the change in internal energy of system.

Q: standard enthalpy change for the following reaction to be -208.6 kJ : CO(g) + 3 H2(g)CH4(g) +…

A:

Q: A chemist measures the enthalpy change AH during the following reaction: Sg(s) + 24 F,(g)→8 SF,(g)…

A: (i) +9672 kJ (ii) -2618 kJ (iii) +1612 kJ

Q: Which of the following is a statement of Hess's law?     If a reaction is carried out in a series of…

A: Thermodynamics is branch of chemistry in which we deal with amount of heat absorbed or evolved…

Q: A system does 546 kJ of work and loses 271 kJ of heat to the surroundings. What is the change in…

A: Work (w) = -546 KJ (because work is done on the surrounding, so this is negative) Heat (q) = -271 KJ…

Q: A scientist measures the standard enthalpy change for the following reaction to be 6.7 kJ : CO(g) +…

A:

Q: A scientist measures the standard enthalpy change for the following reaction to be 208.5 kJ :…

A:

Q: A scientist measures the standard enthalpy change for the following reaction to be 158.9 kJ:…

A:

Q: When 1.42 g of iron reacts with 1.80 g of chlorine, 3.22 g of iron(II) chloride (FeCl2, molar mass =…

A: Iron reacts with chlorine to form iron(II) chloride. When 3.22 g of  is formed, 6.8 kJ of heat is…

Q: A chemical reaction takes place in an open flask. The reaction releases 355 kJ of heat and does 25…

A: According to the first law of thermodynamics the internal energy of a system can be mathematically…

Q: A scientist measures the standard enthalpy change for the following reaction to be-138.9 kJ: H;(2) +…

A: The standard enthalpy change of a system represents the heat content of a system or the heat…

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.