Which of the following processes have positive value for `Delta H`?
`H_(2)(g)rarr2H(g)`
`H^(+)(aq)+OH^(-)(aq)rarr H_(2)O(l)`
`H(g)rarr H^(+)(g)+e^(-)`
`H_(2)O(l)rarr H_(2)O(s)`

Predict the sign of DeltaS for each of the following process: a. O_(2)(g) rarr 2O(g) b. N_(2)(g) +3H_(2)(g) rarr 2NH_(3)(g) c. C(s) +H_(2)O(l) rarr CO(g) +H_(2)(g) d. Br_(2)(l) rarr Br_(2)(g) e. N_(2)(g, 10 atm) rarr N_(2)(g,1atm) f. Desalination of water. g. Devitrification of glass h. Hard boiling of an egg i. C(s, "graphite") rarr C(s, "diamond")

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

For a process H_(2)O(s) rarr H_(2)O(l) at 273 K

For each reaction, wheter the sign of Delta S (entropy) is positive or negative ? (a) Ni(s)+4CO(g)rarr Ni(CO)_(4)(g) (b) 4Fe(s)+3O_(2)(g)rarr 2Fe_(2)O(s) (c ) H_(2)(g)+S(s)rarr H_(2)S(g) (d) 2NO(g)+O_(2)(g)rarr 2NO_(2)(g)

Using the following thermochemical data. C(S)+O_(2)(g)rarr CO_(2)(g), Delta H=94.0 Kcal H_(2)(g)+1//2O_(2)(g)rarr H_(2)O(l), Delta H=-68.0 Kcal CH_(3)COOH(l)+2O_(2)(g)rarr 2O_(2)(g)rarr 2CO_(2)(g)+2H_(2)O(l), Delta H=-210.0 Kcal The heat of formation of acetic acid is :-

On the basis of the following thermochemical data : (Delta_(f)G^(@)H_((aq.))^(+)=0) H_(2)O_((l))rarr H_((aq.))^(+)+OH_((aq.))^(-),DeltaH=57.32kJ H_(2(g))+(1)/(2)O_(2(g))rarrH_(2)O_((l)),DeltaH=-286.20kJ The value of enthalpy of formation of OH^(-) ion at 25^(@)C is :

H_(2)(g)+(1)/(2)O_(2)(g)rarrH_(2)O(l), DeltaH =- 286 kJ 2H_(2)(g)+O_(2)(g)rarr2H_(2)O(l)……………kJ(+-?)

Complete the following chemical equations : (i) P_(4) (s) +NaOH (aq) +H_(2)O (l) to (ii) I^(-) (aq) +H_(2)O (l) +O_(3) (g) to

In how many of the following entropy increases? {:((a) N_(2(g)) + 3H_(2(g)) rarr 2NH_(3(g)),(b)PCl_(5(g)) rarr PCl_(3(g)) + Cl_(2(g))),((c ) H_(2)O_((s)) rarr H_(2)O_((g)),(d)H_(2)O_((l)) rarr H_(2)O_((g))),((e ) 2NaHCO_(3(s)) rarr Na_(2)CO_(3(s)) + H_(2)O_((g)) + CO_(2(g)),(f ) NH_(2)CO_(2)NH_(4(s)) rarr 2NH_(3(g)) + CO_(2(g))),((g) H_(2)O_((l)) rarr H_(2)O_((s)),(h) CO_(2(s)) rarr CO_(2(g))):}

Consider the following reactions: I. C(s) + 1/2 O_(2)(g) rarr CO(g)," "Delta H_(1) = x_(1) II. CO(g) + 1/2 O_(2)(g) rarr CO_(2)(g), " "Delta H_(2) = x_(2) III. C(s) + CO_(2)(g) rarr 2CO(g)," "Delta H_(3) = x_(3) Select the correct statements: