CHEMISTRY TEXTBOOK

-Q : Heat is released by the system to the surroundings. +W : Work is done on the system by the surroundings. -W : Work is done ...

4.4.2 Units of energy and work 1 J = 1 kg m^2 s-2 = 1 Pa m^3 1 Pa = 1 kg m-1 s-2 From to Eq. (4.5), W = - Pext^ ∆V, if pressure ...

The work (W) would be maximum when ∆P is smallest. This means the opposing force (Pex) must be infinitesimally smaller than the ...

Replacing V 2 /V 1 in Eq. (4.10) by P 1 /P 2 , We have Wmax = -2.303 nRT log P 1 P 2 (4.11) Problem 4.4 : 2 moles of an ideal ga ...

A transfer of energy (as heat or work) from the system would change its internal energy. To know ∆U the energy supplied to or re ...

iii. Isochoric process : Substitution of W = -Pext ∆V into Eq. (4.12) ∆U = Q - Pext ∆V (4.16) As the reaction is carried out in ...

Substitution of Eq. (4.26) into Eq. (4.25) yields ∆H = ∆U + n 2 RT - n 1 RT = ∆U + (n 2 - n 1 ) RT = ∆U + ∆ng RT (4.27) where ∆n ...

iii. If n 1 = n 2 , ∆ng = 0 and W = 0, or No PV work is done when number of moles of reactants and products are equal. 4.9 Entha ...

The electron gain enthalpy on the other hand, gives the enthalpy change when one mole of gas-phase atoms of an element accept el ...

On the other hand, if ∑ Hproducts < ∑ Hreactants, ∆rH is negative which means that heat is released and the reaction is exoth ...

(^) The standard enthalpy of formation of a compound is the enthalpy change that accompanies a reaction in which one mole of pur ...

Try this... Write thermochemical equation for complete oxidation of one mole of H 2 (g). Standard enthalpy change of the reactio ...

Examples 4.12 : Calculate the standard enthalpy of : N 2 H 4 (g) + H 2 (g) 2 NH 3 (g) if ∆H^0 (N-H) = 389 kJ mol-1, ∆H^0 (H-H) = ...

4.10.9 Hess’s law of constant heat summation The law states that, “Overall the enthalpy change for a reaction is equal to sum of ...

Do you know? i. The aqueous NaOH and HCl solutions mixed together. NaOH immediately combines with HCl to form NaCl and water. Na ...

iii. When liquid water vaporises, gaseous water molecules move freely and randomly in the available space. A less disordered sta ...

From above examples, it is clear that the entropy of the system increases in the spontaneous processes. Consider the reaction. 2 ...

If ∆H is the enthalpy change accompanying a reaction (system) the enthalpy change of the surroundings is -∆H. With ∆Ssurr = - ∆H ...

When the reaction reaches equilibrium, ∆G^0 = 0 and Qc and Qp become Kc and Kp, respectively. Thus, 0 = ∆G^0 + RT ln Kc and 0 = ...

Problem 4.19 : Calculate ∆Stotal and state whether the reaction is spontaneous or nonspontaneous at 25^0 C. HgS(s) + O 2 (g) Hg( ...