Mark the incorrect statement:
A) Hypophosphorous acid reduces `AgNO_(3)`to metallic silver.
B) Low temperature and high pressure are the favourable conditions for maximum yield in the contact process.
C) HF is more volatile than `H_(2)SO_(4)`
D) Monoclinic sulphur is more stable than rhombic sulphur at room temperature.

Which statement is correct when adsorption of gas take place on metal surface? (a) delta H becomes less negative with pregress of reaction. (b) with progress of reaction the strength of residual forces increases. (c) NH_3 is adsorbed more than N_2 . (d) Equilibrium concentration of adsorbate increases with increase in temperature.

Assign reason for the following : (i) H_(3)PO_(2) is a stronger reducing agent than H_(3)PO_(4) . (ii) Sulphur shows more tendency for catenation than oxygen. (iii) Reducing character increases from HF to HI.

How is ammonia prepared on a large scale ? Name the process and mention the optimum conditions for the production of ammonia by this process. (b) Assign reasons for the following : (i) H_(2)S is more acidic than H_(2)O (ii) NH_(3) is more basic than PH_(3) (iii) Sulphur has a greater tendency of catenation than oxygen

Read the following statement . a) High H^+ concentration and higher temperature are favourable for dissociation of oxygen from oxyhaemoglobin. b) Partial pressure of oxygen in alveoli is higher than in tissue . c) The maximum volume of air a person can breather in after a forced expiration is vital capacity. d) In alveoli PCO_2 low and PO_2 high are for dissociation of CO_2 from carbamino haemoglobin . How many of the above statement are true ?

For a process top be spontaneous, at constant temperature and pressure, there must be decreases in free energy of the system in the direction of the process, i.e. DeltaG_(P.T.)lt0.Delta_(P.T.)=0 implies the equilibrium condition and DeltaG_(P.T.)gt0 corresponding to non-spontaneity. Gibb's Helmholtz equation relates the free energy change to the enthalpy and entropy change of the process as : DeltaG_(P.T.)=DeltaH-TDeltaS ......(i) The magnitude of Delta H does not change much with the change in temperature but the entropy factor TDeltaS changes appreciably. Thus, spontaneity of a process depends very much on temperature. For edothermic proces, both DeltaH "and " DeltaS are positive. The energy factor,the first factor of equation, opposes the spontaneity whereas entropy factor favours it . At low temperature, the favourable factor TDeltaS will be small and may be less than Delta H, DeltaG will have positive value indicating the non-spontaneity of the process. On raising temperature, the factor TDeltaS increases appreciably and when it exceeds DeltaH,DeltaG would become negative and the process would be spontaneous. For an exothermic process, both DeltaH " and " DeltaS would be negative. In this case, the first factor of equation(i) favours the spontaneity whereas the second factor opposes it. At high temperature, when TDeltaSgt DeltaH, DeltaG will have positive value, showing thereby the non-spontaneity of the process. However, on decreasing temperature, the factore TDeltaSlt DeltaH,DeltaG becomes negative and the process occurs spontaneously. Thus, an exothermic process may be spontaneous at low temperature and non-spontaneous at high temperature. When CaCO_(3) is heated to a high temperature, it undergoes decomposition into CaO and CO_(2) whereas it is quite stable at room temperature. The most likely explanation of it, is:

Dependence of Spontaneity on Temperature: For a process to be spontaneous , at constant temperature and pressure , there must be decrease in free energy of the system in the direction of the process , i.e. DeltaG_(P.T) lt 0. DeltaG_(P.T) =0 implies the equilibrium condition and DeltaG_(P.T) gt 0 corresponds to non- spontaneity. Gibbs- Helmholtz equation relates the free energy change to the enthalpy and entropy changes of the process as : " "DeltaG_(P.T) = DeltaH-TDeltaS" ""..."(1) The magnitude of DeltaH does not change much with the change in temperature but the entropy factor TDeltaS change appreciably . Thus, spontaneity of a process depends very much on temperature. For endothermic process, both DeltaH and DeltaS are positive . The energy factor, the first factor of equation, opposes the spontaneity whereas entorpy factor favours it. At low temperature the favourable factor TDeltaS will be small and may be less than DeltaH, DeltaG will have positive value indicated the nonspontaneity of the process. On raising temperature , the factor TDeltaS Increases appreciably and when it exceeds DeltaH, DeltaG would become negative and the process would be spontaneous . For an expthermic process, both DeltaH and DeltaS would be negative . In this case the first factor of eq.1 favours the spontaneity whereas the second factor opposes it. At high temperature , when T DeltaS gt DeltaH, DeltaG will have positive value, showing thereby the non-spontaneity fo the process . However , on decreasing temperature , the factor , TDeltaS decreases rapidly and when TDeltaS lt DeltaH, DeltaG becomes negative and the process occurs spontaneously. Thus , an exothermic process may be spontaneous at low temperature and non-spontaneous at high temperature. When CaCO_(3) is heated to a high temperature , it undergoes decomposition into CaO and CO_(2) whereas it is quite stable at room temperature . The most likely explanation of it, is