Exothermic or Endothermic?

Slides:

Advertisements

Similar presentations

Basic Thermochemistry

Advertisements

Thermochemistry.

Energy and Chemical Reactions Energy is transferred during chemical and physical changes, most commonly in the form of heat.

CHEMISTRY 161 Chapter 6

SCH 4U – Chapter 5.1 Changes in Matter and Energy

THERMODYNAMICS Courtesy of lab-initio.com. Definitions #1 Energy: The capacity to do work or produce heat Potential Energy: Energy due to position or.

Calorimetry & Enthalpy Changes

Calorimetry How to use math to describe the movement of heat energy Temperature Change Problems Temperature Change Problems Phase Change Problems Phase.

Aim: How to measure molar heat of solution DO NOW: Get into groups of 3 or 4 and compare your homework. You have 5 minutes.

Energy Transformations Thermochemistry is the study of energy changes that occur during chemical reactions and changes in state. The energy stored in the.

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

Thermo- Chemistry Heat Transfer Thermo Equations Phase changes F.

calorimetry The measurement of heat in a reaction is called calorimetry. Through this, we find that different substance require different amounts of heat.

Enthalpy Enthalpy is a measure of the total energy of a system. Enthalpy is a state function (the pathway does not matter) with the symbol H. H = E + P.

Thermochemistry. A look at the new unit Chapter 11: Thermochemistry –Endothermic –Exothermic –Changes in states of water Chapter 19.3 and 19.4: Spontaniety.

“Why do we want to burn propanol?” C 3 H 8 +  H 2 O + CO 2 C 3 H 8 +  H 2 O + CO 2 There is another non chemical product…. There is another non.

Energy Changes.

Molar Enthalpy of Vaporization

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.

Molar Enthalpies.  use proper scientific terminology to describe molar enthalpies  calculate molar enthalpies  Calculate molar enthalpies using the.

Thermochemistry Energy Heat Thermochemical Equations Calculating Enthalpy Change Reaction Sponteneity.

Thermochemistry is the study of heat change in chemical reactions. Chapter 5 Energy & Rates of Reaction Unit 3.

Energy and Chemical Reactions Energy is transferred during chemical and physical changes, most commonly in the form of heat.

+ Chemical Energy. + Hmmm… Can you list 5 energy sources that do not directly produce carbon dioxide?

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

THERMOCHEMISTRY. Definitions #1 Energy: The capacity to do work or produce heat Potential Energy: Energy due to position or composition Kinetic Energy:

STAAR Ladder to Success Rung 9. Energy Defined as the ability to do work or produce heat Many forms – Light energy – Nuclear energy – Electrical energy.

Enthalpy The Meaning of Enthalpy. 1. Enthalpy is a state function with the symbol H. H = E + PV E is the internal energy of the system, P is the pressure.

THERMOCHEMISTRY. Definitions #1 Energy: The capacity to do work or produce heat Potential Energy: Energy due to position or composition Kinetic Energy:

1. Definition Heat flow in a system SymbolH Like internal energy, the change in enthalpy is important State function – measure of its current conditions.

Thermochemistry Some Like It Hot!!!!!. The Flow of Energy ► Thermochemistry – concerned with heat changes that occur during chemical reactions ► Energy.

Basic Thermochemistry Courtesy of lab-initio.com.

THERMOCHEMISTRY. Definitions #1 Energy: The capacity to do work or produce heat Potential Energy: Energy due to position or composition Kinetic Energy:

What’s the MATTER: Specific Heat of Matter. Matter, Specific Heat of Matter At the conclusion of our time together, you should be able to: 1. Define specific.

Exothermic  When heat is released (given off) by the system into the surroundings, the process is exothermic  H = H final − H initial  H = H products.

Energy change that occurs during a chemical reaction and/or changes in state.

What’s the MATTER: Specific Heat of Matter. Matter, Specific Heat of Matter At the conclusion of our time together, you should be able to: 1. Define specific.

Chapter 11 Thermo chemistry Heat and Chemical Change The Flow of Energy – Heat Measuring and Expressing Heat Changes Heat in Changes of State Calculating.

THERMOCHEMISTRY. Definitions #1 Energy: The capacity to do work or produce heat Potential Energy: Energy due to position or composition Kinetic Energy:

Heat Problems There are a few problems that deal with heat: There are a few problems that deal with heat: –Heat as enthalpy –Specific heat –Heat of fusion.

Calorimetry and Enthalpy

5.2 Calorimetry and Enthalpy

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

ENERGY n The ability to do work n remains constant in amount during a chemical or physical change n energy changes occur between the system and the surrounding.

Unit 1.  Energy cannot be created or destroyed  Energy can be transferred  “Cooling” is the transfer of heat energy from an object to its surroundings.

Chapter 10 Causes of Change

Thermo-chemistry Topical outline.

Thermo-chemistry.

Thermochemistry.

Unit 3: Energy Changes & Rates of reaction

Energy Changes and Rates of Reaction

Chapter 17 Thermochemistry 17.2 Measuring and Expressing

Capacity to do work or to produce heat

Energy and Rates [Thermochemistry]

Chapter 5 Changes in Matter and Energy

Chapter 5 Changes in Matter and Energy

CHAPTER 10 ENERGY.

Calorimetry and Enthalpy

Calorimetry Calorimetry is the measurement of the heat flow into or out of a system for chemical and physical processes. Copyright © Pearson Education,

Bond Energy and Reaction Energy

Intro to Thermochemistry

Calorimetry Thermochemistry pt2.

Unit 3: Energy Changes & Rates of reaction

Thermochemistry Thermochemistry the study of the energy changes that accompany physical or chemical changes in matter. Changes may be classified.

THERMODYNAMICS Courtesy of lab-initio.com.

Chapter Six: THERMOCHEMISTRY.

Quiz A reaction that releases heat is called?

Reaction Energy.

Heating Curves and Enthalpy

Presentation transcript:

Exothermic or Endothermic? Exothermic releases energy into the surrounding as heat. As a result, the temperature of the surrounding increases. Endothermic absorbs energy from the surrounding. As a result, the temperature of the surrounding decreases.

Endothermic or Exothermic?

5.2 Calorimetry and Enthalpy

Task Read pages 292-297 In your notebook, write the definitions of the keywords

Specific Heat Capacity Substance A has a specific heat capacity of 4.18 and substance B has specific heat capacity of 2.03. What does this mean? This means that A needs more thermal energy than B to raise the temperature of A by 1 degrees.

Calorimetry Calculations q = mcΔT q= total amount of thermal energy absorbed or released m=mass of the substance c=specific heat capacity ΔT = change in temperature (final-initial)

Sample Problem 1 Let’s do sample problem 1 from page 295 together!

You have to finish it in class! Task Do questions 1-8 from the handout. You have to finish it in class!

Enthalpy Change Enthalpy (H) the total amount of thermal energy in a substance Enthalpy Change (ΔH) the energy released to or absorbed from the surroundings during a chemical or physical change Molar Enthalpy Change (Δ 𝐻 𝑟 ) the enthalpy change associated with a physical, chemical, or nuclear change involving 1 mol of a substance.

Calculating ΔH It is hard to find the enthalpy (H) of a given substance but we can calculate enthalpy change (ΔH) of a reaction What is ΔH? ΔH = 𝐻 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − 𝐻 𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠 If ΔH > 0, endothermic reaction (positive) If ΔH < 0, exothermic reaction (negative) Also, as long as pressure stays constant, ΔH = |q| We know how to calculate q (q = mcΔT) So, if we know q for a reaction, we know the value of ΔH

Molar Enthalpy Change (Δ 𝐻 𝑟 ) is the general formula for molar enthalpy change for any reaction type. There are different types of molar enthalpy changes (Table 2 on page 299):

Connecting Enthalpy Change and Molar Enthalpy Change The amount of enthalpy change depends on the quantity of matter that undergoes the change For example, it takes more energy to convert 1 L of liquid water to water vapor than it does for 500 mL So, to calculate the enthalpy change for some amount of substance other than 1 mol, you need to use the following formula: ΔH = nΔ 𝐻 𝑟

Task Copy down Sample Problem 1 and 2 from the board

HOMEWORK Required Reading: p. 292-306 Make notes on Representing Molar Enthalpy Changes and copy down the sample problems Do practice problems 1-4 from page 301 Do questions 1-7 on page 306