Question

For each of the following steps, state which of the quantities, delta U, deltaH, deltaS, deltaG, deltaA are equal to zero for system specified:

(a) a nonideal gas is taken around a Carnot cycle

(b) a nonideal gas is adiabatically expanded

(c) An ideal gas is adiabatically expanded. (d) Liquid water is vaporized at 100 oC and 1 atm
(e) H2 and O2 react to form H2O in a perfectly thermally isolated container
(f) HCl and NaOH react to form H2O and NaCl in an aqueous
solution at constant T and P.

Answer 1

(a) a nonideal gas is taken around a Carnot cycle:

delta U, delta H, delta S, delta G and delta A all are equal to zero.

(b). a nonideal gas is adiabatically expanded:

delta H is equal to zero.

(c). An ideal gas is adiabatically expanded.

delta S is equal to zero.

(d). Liquid water is vaporized at 100 oC and 1 atm.

delta G is equal to zero.

(e) H2 and O2 react to form H2O in a perfectly thermally isolated container:

delta U is equal to zero.

(f) HCl and NaOH react to form H2O and NaCl in an aqueous solution at constant T and P.

None of them is zero.