मराठी
महाराष्ट्र राज्य शिक्षण मंडळएचएससी विज्ञान (सामान्य) इयत्ता १२ वी

Define the Bond enthalpy.

Advertisements
Advertisements

प्रश्न

Define the Bond enthalpy.

व्याख्या
Advertisements

उत्तर

The enthalpy change required to break a particular covalent bond in one mole of the gaseous molecule to produce gaseous atoms and/or radicals is called bond enthalpy.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Chemical Thermodynamics - Long answer questions

संबंधित प्रश्‍न

Answer in brief.

How will you calculate reaction enthalpy from data on bond enthalpies?


Answer the following question.

State Hess’s law of constant heat summation. Illustrate with an example. State its applications.


The enthalpy change for the reaction, \[\ce{C2H4_{(g)} + H2_{(g)} -> C2H6_{(g)}}\] is −620 J when 100 mL of ethylene and 100 ml of \[\ce{H2}\] react at 1 bar pressure. Calculate the pressure volume type of work and ΔU for the reaction.


The standard enthalpy of formation of water is - 286 kJ mol-1. Calculate the enthalpy change for the formation of 0.018 kg of water.


Calculate the standard enthalpy of combustion of CH4(g) if ΔfH°(CH4) = – 74.8 kJ mol–1, ΔfH°(CO2) = – 393.5 kJ mol–1 and ΔfH°(H2O) = – 285.8 kJ mol–1.


Calculate the standard enthalpy of formation of liquid methanol from the following data:

  1. \[\ce{CH3OH_{(l)} + \frac{3}{2} O_{2(g)} -> CO_{2(g)} + 2H2O_{(l)}}\]     ∆H° = – 726 kJ mol–1
  2. \[\ce{C_{(Graphite)} + O_{2(g)} -> CO_{2(g)}}\]          ∆cH° = – 393 kJ mol–1
  3. \[\ce{H_{2(g)} + \frac{1}{2} O_{2(g)} -> H2O_{(l)}}\]          ∆fH° = – 286 kJ mol–1 

Classify the following into intensive and extensive properties.

Pressure, volume, mass, temperature.


When 2 moles of C2H6(g) are completely burnt, 3129 kJ of heat is liberated. If ∆Hf for CO2(g) and H2O(l) are −395 and −286 kJ per mole respectively, the heat combustion of C2H6(g) is ____________.


When 6.0 g of graphite reacts with dihydrogen to give methane gas, 37.4 kJ of heat is liberated. What is standard enthalpy of formation of CH4 (g)?


Daily requirement of energy of a person is 'x' kJ. If heat of combustion of food material (Molecular mass = 100 g) is 'y' kJ, his daily consumption of the food in gram would be ____________.


The enthalpy change accompanying a reaction in which 1 mole of the substance in the standard state reacts completely with oxygen or is completely burnt is called as ____________.


Which among the following salts, solubility decreases with increase in temperature?


Enthalpy of formation of two compounds x and y are −84 kJ and −156 kJ respectively. Which of the following statements is CORRECT?


Calculate the enthalpy of hydrogenation of C2H4(g), given that the enthalpy of formation of ethane and ethylene are −30.2 kcal and +12.5 kcal respectively.


Standard entropies of N2(g), H2(g), and NH3(g) are a1, a2 and a3 J K-1 mol-1 respectively. What is value of ΔS° for formation of NH3(g)?


Which of the following equations has ΔfH° and ΔH° same?


Identify the invalid equation.


What is the amount of water formed by the combustion of 1.6 g methane?


The enthalpy change that accompanies a reaction in which 1 mole of its standard state is formed from its elements in their standard states


Which of the following reactions defines the enthalpy of formation?


Standard enthalpy of combustion of a substance is given. Then Write thermochemical equation.

ΔcH0[C2H5OH(1)] = - 1409 kJ mol-1


Standard enthalpy of combustion of a substance is given. Then Write thermochemical equation.

ΔcH0[CH3CHO(l)] = - 1166 kJ mol-1


For the reaction, aA + bB → cC + dD, write the expression for enthalpy change of reaction in terms of enthalpies of formation of reactants and products.


For the reaction, H2 + I2 ⇌ 2HI; ΔH = 12.4 kcal. The heat of formation of HI, ΔHf = ______.


Calculate ΔsubH of the H2O from the given data:
\[\ce{H2O_{(s)}->H2O_{(l)},}\] ΔfusH = 6.01kJ mol−1

\[\ce{H2O_{(l)}-> H2O_{(g)},}\] ΔVapH = 45.07 kJ mol−1.


Calculate the standard enthalpy of combustion of methane if the standard enthalpy of formation of methane, carbon dioxide and water are −74.8, −393.5 and −285.8 kJmol−1 respectively.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×