Home
Class 12
CHEMISTRY
If H(2)+1//2O(2)rarr H(2)O , Delta =-68....

If `H_(2)+1//2O_(2)rarr H_(2)O , Delta =-68.39` Kcal
`K+H_(2)O+ "water" rarr KOH(aq)+1//2H_(2) , Delta H=-48.0` Kcal
`KOH+"water" rarr KOH(aq)Delta H=-14.0` Kcal the heat of formation of KOH is -

A

`-68 + 48 -14`

B

`-68-48 + 14 `

C

`68-48+14`

D

`68 +48 +14`

Text Solution

Verified by Experts

The correct Answer is:
B
Aim. `K(s)+1/2O_2(g)+1/2H_2(g) rarrKOH(s)`
Eqn(ii) + Eqn.(i)-Eqn.(iii) gives
`DeltaH =-48+(-68)-(-14)`
`=- 68-48 +14`
Promotional Banner

Topper's Solved these Questions

  • Chemical Thermodynamics & Energetics

    NIKITA PUBLICATION|Exercise QUESTION FROM COMPETITIVE EXAM|35 Videos

  • CHEMICAL KINETICS

    NIKITA PUBLICATION|Exercise MCQs|351 Videos

  • CHEMISTRY IN EVERYDAY LIFE

    NIKITA PUBLICATION|Exercise MCQs|224 Videos

Similar Questions

Explore conceptually related problems

If H_(2)S+3/2 O_(2) rarr H_(2)O+SO_(2) , DeltaH=-136.7 Kcal H_(2)+1/2 O_(2) rarr H_(2)O, DeltaH=-68.4 Kcal S+O_(2) rarr SO_(2), DeltaH=-71 Kcal What is DeltaH_(f) of H_(2)S

If H_2(g) +I_2(g) rarr 2HI(g), Delta H=12.40 kcal . The enthalpy of formation of HI is

Using the following thermochemical data. C(S)+O_(2)(g)rarr CO_(2)(g), Delta H=94.0 Kcal H_(2)(g)+1//2O_(2)(g)rarr H_(2)O(l), Delta H=-68.0 Kcal CH_(3)COOH(l)+2O_(2)(g)rarr 2O_(2)(g)rarr 2CO_(2)(g)+2H_(2)O(l), Delta H=-210.0 Kcal The heat of formation of acetic acid is :-

DeltaS_(sur) for H_(2)+1//2O_(2) rarr H_(2)O, Delta H = -280 KJ at 400 K is

C_(2)H_(2) + 5/2 O_2(2) rarr 2CO_(2) + H_(2)O , Delta H = -310 kcal C + O_(2) rarr CO_(2) , " "Delta H = -94 kcal H_(2) + 1/2 O_(2) rarr H_(2)O, " " Delta H = -68 kcal On the basis of the above equations, DeltaH_(f) (enthalpy of formation) of C_2H_2 will be :

Given that: i. C(s) + O_(2)(g) rarr CO_(2)(g) , DeltaH =- 94.05 kcal ii. H_(2)(g) +(1)/(2) O_(2)(g) rarr H_(2)O(l), DeltaH =- 68.32 kcal iii. C_(2)H_(2)(g) +(5)/(2) O_(2)(g) rarr 2CO_(2)(g) +H_(2)O(l),DeltaH =- 310.62 kcal The heat of formation fo acetylene is

NIKITA PUBLICATION-Chemical Thermodynamics & Energetics-QUESTION FROM COMPETITIVE EXAM
  1. If H(2)+1//2O(2)rarr H(2)O , Delta =-68.39 Kcal K+H(2)O+ "water" rar...

    Text Solution

    |

  2. For an endothermic reaction where DeltaH represent the enthalpy of rea...

    Text Solution

    |

  3. Standard entropy of X(2) , Y(2) and XY(3) are 60, 40 and 50JK^(-1)mol...

    Text Solution

    |

  4. Match List I (Equations) with List II (Type of processes) and select t...

    Text Solution

    |

  5. Three moles of an ideal gas expanded spontaneously into vacuum. The wo...

    Text Solution

    |

  6. For vaporization of water at 1 atmospheric pressure the values of Delt...

    Text Solution

    |

  7. The following two reactionas are known FeO(3)(s)+3CO(g)rarr2Fe(s)+CO...

    Text Solution

    |

  8. If the enthaply change for the transition of liquid water to steam is...

    Text Solution

    |

  9. Enthalpy change for the reaction, 4H((g))rarr 2H(2(g)) is -869.6 kJ ...

    Text Solution

    |

  10. Consider the following processes :- {:(,DeltaH(kJ//mol)),((1)/(2)A r...

    Text Solution

    |

  11. In view of the signs of Delta(r)G^(0) for the following reactions Pb...

    Text Solution

    |

  12. The value of enthalpy change (DeltaH) for the reaction C(2)H(5)OH (l...

    Text Solution

    |

  13. Consider the reaction, 4NO(2)(g)+O(2)(g)rarr2N(2)O(5)(g),Delta(r )H=...

    Text Solution

    |

  14. Match the transformation in colums I with appropriate options in colum...

    Text Solution

    |

  15. The entropy change involved in the isothermal reversible expansion of ...

    Text Solution

    |

  16. Which of the following is correct option for the free expansion of an ...

    Text Solution

    |

  17. The Gibbs energy for the decomposition of Al(2)O(3) at 500^(@)C is as...

    Text Solution

    |

  18. The entropy change involved in the isothermal reversible expansion of ...

    Text Solution

    |

  19. The incorrect expression among the following is

    Text Solution

    |

  20. In which of the following reactions,standard reaction entropy change(D...

    Text Solution

    |

  21. The enthalpy of fusion of water is 1.435 kcal//"mole". The molar entro...

    Text Solution

    |