F09_230_L9pre[1] - CHEM 230 F09 Lecture 9 Chapter 6...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEM 230 F09 Lecture 9 Chapter 6: Thermodynamics First Law Session ID: 230 Homework 2 due Wed 9/30 at 10pm
Background image of page 1

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

View Full DocumentRight Arrow Icon
a) C12H22O11(s) 12 C(s) + 11 H2O(g) + heat b) heat + 2KClO3(s) 2 KCl(s) + 3O2(g) b) C(s) + O2(g) CO2(g) + heat H2SO4 C Self-Lighting Candle Frozen Beaker Heat + Ba(OH)2& 8H2O(s) + 2NH4SCN(s) Ba(SCN)2(s) + 2NH3(g) + 10 H2O(l) http://www.youtube.com/watch? v=vgh76gPSg3M
Background image of page 2
Measuring Enthalpy Heat exchange: Temperature change q = mC T qa= -qb Phase change Hvap, Hfus Measure with calorimeter Reactions Themochemical equations (adding, reversing, stoichiometry) Hess’s Law Heats of formation Bond enthalpy
Background image of page 3

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

View Full DocumentRight Arrow Icon
Calorimetry Calorimeter: device used to measure the heat absorbed or evolved during a physical or chemical change Constant volume: measures U = qv Constant pressure: measures H = qp = heat of reaction
Background image of page 4
Problem A calorimeter with heat capacity equivalent to 0.739 grams of water is used to measure the heat of combustion of 0.303 g of sucrose (C12H22O11 MW = 342 g/mol). The temperature increase was found to be 5.00oC. Calculate the would be released by this reaction C12H22O11 (s) + O2(g) G CO2(g) + H2O(g) qrxn = -qCal = -mCH2O T = -0.739g (4.184 J )(+5oC) goC = -15.46 J Cs,H2O = 4.184 J/goC
Background image of page 5

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

View Full DocumentRight Arrow Icon
Concept Question Is the energy that we just calculated, the energy associated with the combustion reaction as written? A calorimeter with heat capacity equivalent to 0.739 grams of water is used to measure the heat of combustion of 0.303 g of sucrose (C12H22O11 MW = 342 g/mol). The temperature increase was found to be 5.00oC. Calculate the would be released by this reaction C12H22O11 (s) + O2(g) L CO2(g) + H2O(g) Hrxn= - 15.46 J? Yes or No
Background image of page 6
Thermochemical Equations C(s, graphite) + O2(g)→ CO2(g) ΔH = -393.509 kJ 2C(s, graphite) + 2O2(g)→ 2CO2(g) ΔH = -787.018 kJ (*2) 4C(s, graphite) + 4O2(g)→ 4CO2(g) ΔH = -1574.04 kJ (*4) CO2(g) → C(s, graphite) + O2(g) ΔH = 393.509 kJ (reversed) Which are exothermic, which endothermic?
Background image of page 7

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

View Full DocumentRight Arrow Icon
Assuming gasoline and diesel engines consume the same number of moles of fuel, and lose the same amount of
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 28

F09_230_L9pre[1] - CHEM 230 F09 Lecture 9 Chapter 6...

This preview shows document pages 1 - 9. Sign up to view the full document.

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