107 EXP 6 Lecture

107 EXP 6 Lecture - Sig Figs Specific Heat 1 Heat Capacity for the reaction system 2 Heat(Use q = Cp ΔT 3 Total Enthalpy Data Entry •

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

View Full Document Right Arrow Icon
Chemistry 107 Experiment 6 Heats of Reaction
Background image of page 1

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

View Full DocumentRight Arrow Icon
Precautions Hydrochloric Acid (HCl) – IT HURTS! Unknowns metal oxides or hydroxides Potential skin irritants
Background image of page 2
First Law of Thermodynamics E = q + w E = total energy q = heat w = work = -Δ(PV) = -PΔV (at constant P) ΔE = q – PΔV Use H = E + PV =>> ΔH = ΔE + Δ(PV)
Background image of page 3

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

View Full DocumentRight Arrow Icon
How to assemble the apparatus Stir plate Thermometer Foam Cal. Body Stopper 6 dram vial Stir Bar Unknown 10 ml HCl 23. 4 STIR PLATE
Background image of page 4
Temp (oC) Time (min) No data on 4th minute ΔT
Background image of page 5

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

View Full DocumentRight Arrow Icon
Calculation 4.03 J g-1 oC-1 [ (Vol HCl ml) (den of HCl g ml-1) Mass of unknown g [ + = Cp sys G. For the reaction system : qsys = Cp sys ΔT Δ H = qsys + qcal # grams of unknown H. For calorimeter : qcal = Cp cal ΔT (Cp cal = 7.5 J/oC ) ΔT < 10.0 # sig figs = 2 10.0 < ΔT < 13.3 # sig figs = 3
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Sig Figs Specific Heat 1. Heat Capacity for the reaction system 2. Heat (Use q = Cp ΔT) 3. Total Enthalpy Data Entry • chem107.chem.byu.edu • Use Excel sheet for calculating ∆ T and all calculation • Be careful of using data points to get ∆ T • Choose the best data (at least two data) • Put the data in “Data Entry” (there should be no blank between trials) In Lab • Group experiment (4 members) • Check all thermometers using cold and hot water in beakers (temp. difference should be closed each ) • Run 1 (one per group is sufficient) • Use unknown mass for ∆ T = 10.1~13.0 oC if possible • Backpack should be in the locker (don’t interrupt other people with your backpack)....
View Full Document

This note was uploaded on 04/07/2011 for the course CHEM 107 taught by Professor Staff during the Winter '08 term at BYU.

Page1 / 8

107 EXP 6 Lecture - Sig Figs Specific Heat 1 Heat Capacity for the reaction system 2 Heat(Use q = Cp ΔT 3 Total Enthalpy Data Entry •

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

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