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

Select the most appropriate option. If the standard enthalpy of formation of methanol is –238.9 kJ mol–1 then entropy change of the surroundings will be _______. - Chemistry

Advertisements
Advertisements

प्रश्न

Select the most appropriate option.

If the standard enthalpy of formation of methanol is –238.9 kJ mol–1 then entropy change of the surroundings will be _______. 

पर्याय

  • –801.7 J K–1

  • 801.7 J K–1

  • 0.8017 J K–1

  • –0.8017 J K–1

MCQ
Advertisements

उत्तर

If the standard enthalpy of formation of methanol is –238.9 kJ mol–1 then entropy change of the surroundings will be 801.7 J K–1.

Explanation:

For standard state, temperature = 298 K

`triangle "S"_"surr" = - (triangle "H")/"T" = - ((- 238.9  "kJ"))/(298 "k")`

= + 0.8017 kJ K-1

= 801.7 J K-1 

shaalaa.com
Enthalpy (H)
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Chemical Thermodynamics - Exercises [पृष्ठ ८७]

APPEARS IN

बालभारती Chemistry [English] Standard 12 Maharashtra State Board
पाठ 4 Chemical Thermodynamics
Exercises | Q 1.07 | पृष्ठ ८७

संबंधित प्रश्‍न

Select the most appropriate option.

The enthalpy of formation for all elements in their standard states is _______.


Calculate the work done in the decomposition of 132 g of \[\ce{NH4NO3}\] at 100°C.

\[\ce{NH4NO3_{(s)} -> N2O_{(g)} + 2H2O_{(g)}}\]

State whether work is done on or by the system.


Answer the following question.

Calculate standard enthalpy of reaction,

Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g), from the following data.

Δf H°(Fe2O3) = - 824 kJ/mol,

Δf H°(CO) = - 110 kJ/mol,

Δf H°(CO2) = - 393 kJ/mol


Answer the following question.

Calculate ΔU at 298 K for the reaction,

C2H4(g) + HCl(g) → C2H5Cl(g), ΔH = - 72.3 kJ

How much PV work is done?


Calculate the amount of work done in the

1) Oxidation of 1 mole HCl(g) at 200 °C according to reaction.

4HCl(g) + O2(g) → 2Cl2(g) + 2H2O(g)

2) Decomposition of one mole of NO at 300 °C for the reaction

2NO(g) → N2(g) + O2(g)


Answer the following question.

When 6.0 g of O2 reacts with CIF as per 

\[\ce{2ClF_{(g)} + O2_{(g)} -> Cl2O_{(g)} + OF2_{(g)}}\]

The enthalpy change is 38.55 kJ. What is the standard enthalpy of the reaction? (Δr H° = 205.6 kJ)


Calculate the work done and comment on whether work is done on or by the system for the decomposition of 2 moles of NH4NO3 at 100 °C
NH4NO3(s) → N2O(g) + 2H2O(g)


Write the mathematical relation between ΔH and ΔU during the formation of one mole of CO2 under standard conditions.


Write the expression showing the relation between enthalpy change and internal energy change for gaseous phase reaction.


Enthalpy of neutralization is always a constant when a strong acid is neutralized by a strong base: account for the statement.


The standard enthalpy of formation of ammonia is −46.0 kJ mol−1. The enthalpy change for the reaction:

\[\ce{2NH3_{(g)} -> 2N2_{(g)} + 3H2_{(g)}}\] is ____________.


For which of the following ∆U = ∆H?


The difference between heats of reaction at constant pressure and at constanl volume for the reaction

\[\ce{2C6H6_{(l)} + 15O2_{(g)} -> 12CO2_{(g)} + 6H2O_{(l)}}\] at 25°C in kJ


When 6.0 g of O2 reacts with CIF as per \[\ce{2ClF_{(g)} + O2_{(g)} -> Cl2O_{(g)} + OF2_{(g)}}\] the enthalpy change is 38.55 kJ. The standard enthalpy of the reaction is ____________.


Identify the equation in which change in enthalpy is equal to change in internal energy.


The enthalpy change for two reactions are given by the equations

\[\ce{2Cr_{(s)} + 1.5 O2_{(g)} -> Cr2O3_{(s)}}\];

∆H1 = −1130 kJ ............(i)

\[\ce{C_{(s)} + 0.5 O2_{(g)} -> CO_{(g)}}\];

∆H2 = −110 kJ .........(ii)

What is the enthalpy change, in kJ, for the following reaction?

\[\ce{3C_{(s)} + Cr2O3_{(s)} -> 2Cr_{(s)} + 3CO_{(g)}}\]


Given the bond energies N ≡ N, H – H and N – H bonds are 945, 436 and 391 kJ/mol respectively. The enthalpy of the reaction;

\[\ce{N2_{(g)} + 3H2_{(g)} -> 2NH3_{(g)}}\]


In which of the following reactions does the heat change represent the heat of formation of water?


In which of the following reactions, ∆H is greater than ∆U?


Work done when 2 moles of an ideal gas is compressed from a volume of 5 m3 to 1 dm3 at 300 K, under a pressure of 100 kPa is ____________.


For the reaction, \[\ce{N_{2(g)} + 3H_{2(g)} -> 2NH_{3(g)}}\], ΔH is equal to ______.


What is the amount of work done when 0.5 mole of methane, CH4 (g), is subjected to combustion at 300 K? (Given, R = 8.314 JK-1mol-1)


The work done during combustion of 9 × 10-2 kg of ethane, C2H6 (g) at 300 K is ______.
(Given R = 8.314 J deg-1, atomic mass C = 12, H = 1)


Under what conditions ΔH = ΔU?


Calculate the work done in oxidation of so2(g) at 25°C if, \[\ce{2SO_{2(g)} + O2_{(g)} -> 2SO_{3(g)}}\], R = 8.314 J K−1 mol−1.


In a particular reaction, 2 kJ of heat is released by the system and 8 kJ of work is done on the system. Determine ΔU.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×