Let’s try a question from Friday... When 50 mL of 1.0 mol/L hydrochloric acid is neutralized completely by 75 mL of 1.0 mol/L sodium hydroxide in a polystyrene.

Slides:

Advertisements

Similar presentations

IB Topics 5 & 15 PART 1: Heat and Calorimetry

Advertisements

Energy From Chemical Reactions

Calorimetry 6.03 Honors.

CDO Chemistry Thermodynamics 1 st Law of Thermodynamics 1 st Law – energy cannot be created or destroyed it can just change forms Energy can be.

Energy and Heat.

Calorimetry: :Measuring Heat

Calorimetry & Enthalpy Changes

Practicing Calorimetry. At the end of this lesson, you will be able to 30–A1.4k write balanced equations for chemical reactions that include energy changes.

Calorimetry: :Measuring Heat

Calorimetry Heat of combustion Heat capacity Solution calorimetry Calibration factor Bomb calorimetry.

Enthalpy and Calorimetry Chapter 5 part 2 Enthalpy H is heat under constant pressure or H=q P H=E+PV And therefore ΔH= ΔE+P ΔV ΔH=H final -H initial.

CHAPTER 17 THERMOCHEMISTRY.

Titration Calculations Practice. Titration Formula: (#H + ) M a V a = M b V b (#OH - )

CALCULATION OF ENTHALPY CHANGES. Molar Enthalpy  the enthalpy change for 1 mole of a substance associated with a chemical, physical or nuclear change.

Reaction Energy and Reaction Kinetics Thermochemistry.

Thermochemistry.

Chapter 25 – Energy from Chemical Reactions. Thermochemical Equations Remember: ΔH = H products – H reactants. The heat of reaction, ΔH, is negative when.

Energy and Heat. Definitions Thermochemistry: the study of the energy changes that accompany chemical reactions Energy: A property of matter describing.

Chapter 5- Part 2 Thermochemistry

Thermodynamics: Energy Relationships in Chemistry The Nature of Energy What is force: What is work: A push or pull exerted on an object An act or series.

CALORIMETRY ΔH of a chemical rxn can experimentally be determined by measuring the heat flow accompanying the rxn at constant pressure. When heat flows.

Leave space between each step to add more information. 1.Write a balance chemical equation between the acid and the base. Remember it’s a double replacement.

ENTHALPY, HESS’ LAW, AND THERMOCHEMICAL EQUATIONS.

Thermochemical equations Thermochemical equations  Thermochemical equation = a balanced chemical equation that includes the physical states.

17.2 Measuring and Expressing Enthalpy Changes 1 > Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chapter 17 Thermochemistry.

Question of the Day: Day 4 2-8

General Chemistry, Chapters 4-6 Practice Problems Dr. Badger.

Mole, gas volume and reactions, Chemical energy and Enthalpy,

Topic 5.1 Measuring Energy Changes total energy of the universe is a constant law of conservation of energy – if a system loses energy, it must be gained.

Calorimetry. Since we cannot know the exact enthalpy of the reactants and products, we measure  H through calorimetry, the measurement of heat flow.

200 I’m gassy Let’s bond Stoichiometry Energizer Bunny I have the.

CHAPTER 17 THERMOCHEMISTRY. ENERGY Energy is the capacity to do work or to supply heat. Various forms of energy include potential, kinetic, and heat.

Energy Changes During Chemical Reactions Chemical reactions always result in the breaking of bonds between atoms and the formation of new bonds. Breaking.

How can energy changes in chemical reactions be measured? Calorimetry - the use of temperature changes and specific heat capacities to calculate energy.

Calorimetry Measurement of Enthalpy Change. Specific heat capacity is the amount of heat needed to raise the temperature of 1g of substance by 1K Specific.

Calorimetry is the technological process of measuring energy changes of an isolated system called a calorimeter Calorimetry is the technological process.

A “Calorimeter”. Calorimetry Calculations When analyzing data obtained using a calorimeter, make these assumptions: Any thermal energy transferred from.

Everyday Calorimetry. whenever we heat water, its like using a calorimeter calorimeters are used to compare quantities of different fuels that burn to.

ENTHALPY CHAPTER ELEVEN.

Unit A Thermochemical Changes. The study of energy changes by a chemical system during a chemical reaction is called thermochemistry. Calorimetry is.

U3 S3 L1 Calorimetry Textbook Readings MHR pages : The Technology of Heat Measurement pages : Using a Calorimeter to Determine the Enthalpy.

Quiz 1.In an experiment g of Mg was burnt to heat up 125 g of water, the Initial temperature for water is 25.0 o C, the final temperature is 72.3.

11.2 Calorimetry. The Law of the Conservation of Energy- – Energy is neither created nor destroyed in any physical or Chemical Change But to study this.

IGCSE CHEMISTRY SECTION 4 LESSON 2. Content The iGCSE Chemistry course Section 1 Principles of Chemistry Section 2 Chemistry of the Elements Section 3.

Thermochemistry pt 2. Calorimetry ΔH can be found experimentally or calculated from known enthalpy changes Measure heat flow with a calorimeter Heat capacity.

Molar Enthalpy Recall that when we write a thermochemical equation the coefficients represent moles of particles Therefore, 1 H 2(g) + ½ O 2(g)  1 H 2.

Topic 5.2 Calculations of enthalpy changes.  Specific heat (s) – the amount of heat necessary to raise the temperature of 1 g of a substance by 1 o C.

5.1 ENERGETIC CALCULATIONS IB SL Chemistry Mrs. Page

Enthalpy & Thermochemical Equations Thornburg 2014.

CHAPTER ELEVEN ENTHALPY. Today’s Agenda: Discuss homework worksheet solutions Enthalpy PowerPoint Practice Curricular outcomes: 1.3k: Define enthalpy.

Chem 30 Review. THERMOCHEMISTRY Energy from the Sun Stored energy in the chemical bonds of hydrocarbons originated from the sun Remember: Photosynthesis:

5.2 Calorimetry and Enthalpy

17.2 Measuring and Expressing Enthalpy Changes 1 > Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Chapter 17 Thermochemistry.

5.2 Calorimetry and Enthalpy. Measuring Energy Changes Calorimetry is the experimental process used to measure the transfer of thermal energy. – A bomb.

Question 49 The combustion of .1584g benzoic acid increases the temperature of a bomb calorimeter by 2.54°C. Calculate the heat capacity of this calorimeter.

Topic 5.2 Calculations of enthalpy changes

U3 S2 L2 Calculating Enthalpy Textbook Readings MHR

Chemsheets AS006 (Electron arrangement)

Energy Changes and Rates of Reaction

Chapter 25 – Energy from Chemical Reactions

The Law of Conservation of Energy

Calorimetry and Enthalpy

Lesson # 2: Enthalpy Calculations

Change in Enthalpy State function ΔH = q at constant pressure

Exothermic or Endothermic?

Calorimetry Thermochemistry pt2.

Thermochemistry.

Review Write your answer on a piece of paper:

PART 1: Heat and Calorimetry

Presentation transcript:

Let’s try a question from Friday... When 50 mL of 1.0 mol/L hydrochloric acid is neutralized completely by 75 mL of 1.0 mol/L sodium hydroxide in a polystyrene cup calorimeter, the temperature of the total solution changes from 20.2°C to 25.6°C. Determine the enthalpy change that occurs in the chemical system. Δ r H = Q = mc Δt =(50+75)g x 4.19 J/g°C x ( )°C =2.83 kJ The enthalpy change for the neutralization of HCl in this context is recorder as kJ because it’s an exothermic reaction.

Molar Enthalpies Sometimes it is better to know the enthalpy change per unit chemical amount (i.e. per mole) so that you can relate the enthalpy change to a chemical reaction equation that is balanced in moles. Molar enthalpy of reaction is the enthalpy change in a chemical system per unit chemical amount (per mole) of a specified chemical undergoing change in the system at constant pressure.

Δ r H = nΔ r H m Enthalpy change of reaction Chemical amount (moles) Molar enthalpy of reaction Note: the ‘r’s can be switched with a ‘c’s for combustion reactions

Where do I find molar quantities Molar quantities are often referenced or memorized Atomic molar masses are from the periodic table molar volume of any gasses at STP is 22.4 L/mol We can use these to predict, say, the enthalpy of combustion ( Δ c H)

Sample problem Predict the change in enthalpy due to the combustion of 10.0 g of propane used in a camp stove. 1) First you have to determing the change in enthalpy for the combustion Δ c H Δ c H = nΔ c H m To calculate Δ c H we need to know the chemical amount and molar enthalpy of combustion Δ c H m n= 10.0 g x 1/44.11g/mol (molar mass) Molar enthalpy of combustion of propane is: kJ/mol

Answer Δ c H = nΔ c H m = 10.0 g x 1/44.11 g/mol x ( kJ/mol) = kJ

Another problem Predict the enthalpy change due to the combustion of 10.0g of butane in a camp heater. The molar enthalpy of combustion to produce water vapour is kJ/mol Δ c H = nΔ c H m = 10.0 g x 1/58.14g/mol x ( kJ/mol) = kJ

Remember... Δ H = Q therefore nΔ c H m = mcΔt You can use this to determine an unknown but be careful, in calorimetry, the right hand side is all about water and the left is about the fuel.

Homework Questions 1-7 and 11 on page 494