Problem set 2 Solutions

Problem set 2 Solutions - The standard enthalpy of...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Problem set 2 Solutions 7.26 The reaction absorbs negative heat at constant P, so its ΔH is -670 J. (-670 J/1.00 g CuCl 2 )(134.452 g CuCl 2 /1 mol CuCl 2 ) = -90.0x10 3 J mol -1 7.28 In this process a liquid freezes, so ΔH of the liquid is negative: (-28.8 kJ/1 mol NaCl)(1 mol NaCl/58.44 g NaCl)(56.2x10 3 g NaCl) = -2.77x10 4 kJ
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
7.48 The reaction forming one mole of ethane from ethylene and hydrogen in their standard states can be imagined as breaking all the bonds in the reactants, which are one mole of gaseous ethylene and one mole of gaseous hydrogen, and then constructing one mole of ethane from the resulting gaseous atoms. ΔHº = 4(413)kJ + 1(615)kJ + 1(436)kJ – 6(413)kJ – 1(348)kJ = -123 kJ C-H C=C H-H C-H C-C
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
7.74 (a). C 4 H 8(g) + 6O 2(g) 4CO 2(g) + 4H 2 0 (g)
Background image of page 4
Background image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: The standard enthalpy of formation of isobutene H f = is given by;-2528 kJ = 4(-393.5 kJ) + 4(-241.8 kJ) - H f H f = -13 kJ mol-1 (b). When 0.50 mol of isobutene is burned at constant pressure q p = 0.50(-2528) kJ = -1.26x10 3 kJ If this is done adiabatically, then the heat will be absorbed by the substances present at the conclusion of the reaction and by the reaction vessel; their temperature will rise. There are present 2 mol CO 2 , 2 mol H 2 O and 5 mol O 2 [(2x37) + (2x34) + (5x29) + 700] J K-1 = 987 J K-1 The temperature rise will be about 1.26x10 6 J/987 J K-1 = 1.28x10 3 K Since the initial temperature was nearly 300 K, the final temperature will be near 1600 K, or about 1300C....
View Full Document

Page1 / 5

Problem set 2 Solutions - The standard enthalpy of...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online