Calculate the enthalpy change on freezing of 1.0 mol of water at 10.0°C to ice at – 10.0°C. A, H = 6.03 KJ mot1 at 0°C. Cp [H20(l)J = 75.3 J mol^-1 K^-1; Cp [H20(s)J = 36.8 J mol^-1 K^-1.

Given : N₂(g) + 3H₂(g) ————> 2NH₃(g); ∆_{r H^–} = -92.4 kj mot^-1 What is the standard enthalpy of formation of NH₃ gas?

Calculate the standard enthalpy of formation of CH₃OH. from the following data:
(i) CH₃OH(l) + 3/2 0₂ (g) ———-> CO₂ (g) + 2H₂0 (l); ∆_rH^– = – 726kj mol^-1
(ii) C(s) + 0₂(g) —————>C0₂ (g); ∆_cH^– = -393 kj mol^-1
(iii) H₂(g) + 1/20₂(g) —————->H₂0 (l); ∆_fH^– = -286 kj mol^-1

 For an isolated system∆U = 0; what will be ∆S? 

 For a reaction at 298 K
2A + B————->C
∆H = 40Q kj mot1 and AS = 0.2 kj Kr^-1 mol^-1.
At what temperature will the reaction become spontaneous considering ∆H and ∆S to be constant over the temperature range?

For the reaction; 2Cl(g) ———-> Cl₂(g); what will be the signs of ∆H and ∆S?

If ∆U = 0 how are q and w related to each other?

When is bond energy equal to bond dissociation energy ?

What is the enthalpy of formation of the most stable form of an element in its standard state?
 

Out of diamond and graphite, which has greater entropy

At what temperature entropy of a substance is zero?