{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

F09_230_L9post

# F09_230_L9post - CHEM 230 F09 Lecture 9 Chapter 6...

This preview shows pages 1–8. Sign up to view the full content.

CHEM 230 F09 Lecture 9 Chapter 6: Thermodynamics First Law Session ID: 230 Homework 2 due Wed 9/30 at 10pm

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

View Full Document
a) C 12 H 22 O 11(s) 12 C (s) + 11 H 2 O (g) + heat b) heat + 2KClO 3(s) 2 KCl (s) + 3O 2(g) c) C (s) + O 2(g) CO 2(g) + heat H 2 SO 4 C Self-Lighting Candle Frozen Beaker Heat + Ba(OH) 2 8H 2 O (s) + 2NH 4 SCN (s) Ba(SCN) 2(s) + 2NH 3(g) + 10 H 2 O (l) http://www.youtube.com/watch?v=vgh76gPSg3M
Measuring Enthalpy Heat exchange: Temperature change q = mC Δ T q a = -q b Phase change Δ H vap , Δ H fus Measure with calorimeter Reactions Themochemical equations (adding, reversing, stoichiometry) Hess’s Law Heats of formation Bond enthalpy

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

View Full Document
Calorimetry Calorimeter: device used to measure the heat absorbed or evolved during a physical or chemical change Constant volume: measures Δ U = q v Constant pressure: measures Δ H = q p = heat of reaction
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 (C 12 H 22 O 11 MW = 342 g/mol). The temperature increase was found to be 5.00 o C. Calculate the heat that would be released by this reaction C 12 H 22 O 11 (s) + O 2(g) CO 2(g) + H 2 O (g) q rxn = -q Cal = -mC H2O Δ T = -0.739g (4.184 J )(+5 o C) g o C = -15.46 J C s,H2O = 4.184 J/g o C

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

View Full Document
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 (C 12 H 22 O 11 MW = 342 g/mol). The temperature increase was found to be 5.00 o C. Calculate the would be released by this reaction C 12 H 22 O 11 (s) + O 2(g) CO 2(g) + H 2 O (g) Δ H rxn = -15.46 J? Yes or No
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 (C 12 H 22 O 11 MW = 342 g/mol). The temperature increase was found to be 5.00 o C. Calculate the would be released by this reaction C 12 H 22 O 11 (s) + O 2(g) CO 2(g) + H 2 O (g) Δ H rxn = -15.5 J? Yes

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 31

F09_230_L9post - CHEM 230 F09 Lecture 9 Chapter 6...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online