Home
Class 10
CHEMISTRY
H(2) (g) + (1)/(2) O(2)(g) to H(2)O(l) ...

`H_(2) (g) + (1)/(2) O_(2)(g) to H_(2)O(l)`
`BE (H-H) = x_(1) , BE ( O= O) = x_(2)`
`BE(O-H) = x_(3)`
Latent heat of vaporisation of water liquid into water vapour `= x_(4)` then `Delta_(f)H` (heat of formation of liquid water) is

A

`x_(1) = (x_(2))/(2) - x_(3) + x_(4)`

B

`2x_(3) - x_(1) - (x_(2))/(2) - x_(4)`

C

`x_(1) + (x_(2))/(2) - 2x_(3) - x_(4)`

D

`x_(1)+ (x_(2))/(2) - 2x_(3) + x_(4)`

Text Solution

Verified by Experts

The correct Answer is:
C
`DeltaH = (BE)_("reactant") - (BE)_("products") `
[ But all the species must be in gaseous state . In product , `[H_(2)O(l) to H_(2) o(g)]` `Delta H` must be added.
Hence , `H_(2)(g) + (1)/(2) O_(2)(g) to H_(2)O (l)`
`DeltaH = [(BE)_(H-H) + (1)/(2)(BE)_(O=O)]`
` = [(DeltaH)_(vap) + 2(BE)_(OH)]`
` = x_(1) + (x_(2))/(2) - [x_(4) + 2x_(3)]`
` x_(1) + (x_(2))/(2) - x_(4) - 2x_(3)`
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS AND THERMOCHEMISTRY

    CENGAGE CHEMISTRY|Exercise CHALLENGING EXERCISE |7 Videos

  • REACTION KINETICS AND CHEMICAL EQUILIBRIUM

    CENGAGE CHEMISTRY|Exercise OLYMPIAD AND NTSE LEVEL EXERCISES|10 Videos

Similar Questions

Explore conceptually related problems

H_(2)(g) + 1/2O_(2)(g) rarr H_(2)O (l) , BE (H - H) = x_(1) , BE (O = O) = x_(2) , BE(O-H) = x_(3) Latent heat of vaporization of liquid water into water vapour = x_4 then Delta H_(f) (heat of formation of liquid water) is:

H_(2)O(g)+(1)/(2)O_(2)(g)toH_(2)O(g)," "DeltaH=x H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)," "DeltaH=y heat of vaporization of water is:

For the process, H_(2)O(l) to H_(2)O(g)

H_(2)(g)+1//2O_(2)(g)=H_(2)O(l) , Delta H_(298 K)=-68.32 Kcal. Heat of vapourisation of water at 1 atm and 25^(@)C is 10.52 Kcal. The standard heat of formation (in Kcal) of 1 mole of water vapour at 25^(@)C is

1 mole of H_(2)O is vaporised at 100^(@)C and 1 atm pressure. If the latent heat of vaporisation of water is x J/g, then Delta S in terms of J/mole K is given by