Under the entry H₂SO₄, a reference source lists many values for the standard enthalpy of formation. For example, for pure H₂SO₄(l), Δ_fH° =  -814.0 kJ/mol; for a solution with 1 mol H₂O per mole of H₂SO₄, -841.8; with 10 mol H₂O, -880.5; with 50 mol H₂O, -886.8; with 100 mol H₂O, -887.7; with 500 mol H₂O, -890.5; with 1000 mol H₂O, -892.3; with 10,000 mol H₂O, -900.8; and with 100,000 mol H₂O, -907.3.

(a) Explain why these values are not all the same.

(b) The value of Δ_fH°[H₂SO₄(aq)] in an infinitely dilute solution is -909.3 kJ/mol. What data from this chapter can you cite to confirm this value? Explain.

(c) If 500.0 mL of 1.00 M H₂SO₄(aq) is prepared from pure H₂SO₄(l), what is the approximate change in temperature that should be observed? Assume that the H₂SO₄(l) and H₂O(l) are at the same temperature initially and that the specific heat capacity of the H₂SO₄(aq) is about 4.2 J g^-1 °C^-1.