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Statement-1 : Delta H(f)^(@) is zero for...

Statement-1 : `Delta H_(f)^(@)` is zero for oxygen `(O_(2))`.
And
Statement-2 : `Delta H_(f)^(@)` for all the elements at S.T.P. is zero.

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It is because elements occur naturally but cannot be prepared.
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Statement-1 : Entropy of all elements is zero at zero Kelvin. Statement-2 : Standard entropy of all elements is greater than zero. Statement-3 : Entropy of all elements and compounds decreases with decrease of temperature and becomes zero at absolute zero temperature.

Statement-1: The O-O bond length in H_(2)O_(2) is longer than that of O_(2)F_(2) . Statement-2: H_(2)O_(2) is a polar covalent molcule.

Statement-1 : In a cyclic process, both Delta H and Delta U are zero. And Statement-2 : Delta H and Delta U are path dependent functions.

Statement-1 : H_(2)O is liquid whereas H_(2)S is gas . and Statement-2 : Oxygen is more electronegative than sulphur .

Statement-1 : Delta H and Delta U are the same for the reaction H_(2)(g) + I_(2)(g) hArr 2 HI(g) And Statement-2 : All reactants and products are in gaseous form.

Statement-1: All oxy acid of P are good oxidising agents. Statement-2: H_(3)PO_(2) is monobasic.

Generally alkali metals form their oxides by an average increment of 6 kJ mol^(-1) K^(-1) in their entropies. If at 25^(@)C, Delta G_(f)^(@) of Al_(2)O_(3)(s)=-1582 kJ mol^(-1) , Delta H_(f)^(@) of Li_(2)O(s)=1244 kJ and Delta H_(f)^(@) of Na_(2)O(s)=1411 kJ . The aluminium oxide can be reduced to Al metal by

Statement-1: HNO_(4) acid never exists. Statement-2: H_(2)S_(2)O_(3) is a thionic acid. Statement-3: H_(2)S_(2)O_(7) contain S-S bond.

Statment 1 |Delta_(f)H|" of "(H_(2)O,l)gt|Delta_(f)H|" of "(H_(2)O,g) Statment 2 DeltaH_("condensation") is negative. (a)If both the statements are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1 (b)If both the statements are TRUE but STATEMENT-2 is NOT the correct explanation of STATEMENT-1 (c)If STATEMENT-1 is TRUE and STATEMENT-2 is FALSE (d)If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE

For which Delta_(f)H^(Theta) is zero?

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