EXPERIMENT.

Slides:

Advertisements

Similar presentations

Enthalpy of Solution (HSOLN)

Advertisements

Enthalpy of Neutralisation

Higher Chemistry Unit 1(a) Identifying a reactant in excess.

IB Topics 5 & 15 PART 1: Heat and Calorimetry

Determining the enthalpy of a reaction. Determine the enthalpy of this reaction: Mg(OH) 2 (s) + H 2 SO 4 (aq) → MgSO 4 (aq) + 2H 2 O(l) Method Measure.

Chapter 11 (Practice Test)

Higher Chemistry Unit 1(b) Enthalpy of combustion.

Enthalpy of Neutralisation

Enthalpy of Solution. HIGHER GRADE CHEMISTRY CALCULATIONS Enthalpy of Solution. The enthalpy of solution of a substance is the energy change when one.

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.

Heat Problems 1.Using calories, calculate how much heat 32.0 g of water absorbs when it is heated from 25.0 o C to 80.0 o C. How many joules is this?

Enthalpy Calculations

Titrations How can use titrations to work out the concentration of a chemical Starter: HCl + NaOH  NaCl +H 2 O H + + OH -  H 2 O 1)What do these reactions.

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

A 3.51 g sample of benzene, C 6 H 6, was burned in a bomb calorimeter in an excess of oxygen. The initial temperature was o C and rose to

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

Heat & Enthalpy Changes

Enthalpy Changes Measuring and Expressing ∆H ☾ Calorimetry ☽

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

 Section 5.2. The temperature of a substance increases when heated Heat capacity: the amount of heat energy required to raise the temperature of a substance.

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

Heat of Fusion Hf Energy needed to melt a gram of solid. Fusion = Melting Table B – Reference Tables ◦ 1g ice needs 334J of energy to turn to 1g liquid.

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.

CHEMISTRY DEPARTMENT WAID ACADEMY ENTHALPY. The enthalpy of combustion of methanol, CH 3 OH, is -715 kJ mol -1. The mass of methanol which has to be burned.

Industrial Applications of Chemical reactions

1.4 Energetics Practical 1.4 – Measuring some enthalpy changes

Calculation of Enthalpy Values Using E = c m  T.

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

Jeremy Koo 1 Chemical Energetics & Thermodynamics Q5.

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.

LO- Understand how enthalpy changes of combustion can be measured using calorimetry. Measuring Enthalpy Changes What can you remember from GCSE? The energy.

PPT - AS Calorimetry 28/04/2017 CALORIMETRY.

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.

Chapter 14: Liquids and Solids

Calculations using moles 2

Chemical Calculations

HIGHER GRADE CHEMISTRY CALCULATIONS

Introduction to Energetics

Determining Enthalpy of Rxn by Experiment

Topic 5.2 Calculations of enthalpy changes

Chemsheets AS006 (Electron arrangement)

Chemsheets AS006 (Electron arrangement)

4.3 Measuring enthalpy changes

Refresh Which is true for a chemical reaction in which the products have a higher enthalpy than the reactants? Reaction ∆H A. endothermic positive B. endothermic negative.

Refresh Which is true for a chemical reaction in which the products have a higher enthalpy than the reactants? Reaction ∆H A. endothermic positive.

Heat and Chemical Change

Chemical/physical changes in the lab are open to atmosphere, so the changes occur at a constant pressure Heat content of a system at constant pressure.

Chapter 25 – Energy from Chemical Reactions

IB Topics 5 & 15 PART 1: Heat and Calorimetry

Unit 3 Science Investigation Skills

AQA QUANTITATIVE CHEMISTRY 2

Chemical/physical changes in the lab are open to atmosphere, so the changes occur at a constant pressure Heat content of a system at constant pressure.

Calculating various enthalpy changes

Lesson # 2: Enthalpy Calculations

HIGHER GRADE CHEMISTRY CALCULATIONS

HIGHER CHEMISTRY REVISION.

Measuring Enthalpy Changes

Thermochemistry.

Enthalpy 18/04/2019.

Match the terms to their definitions

Chemsheets AS006 (Electron arrangement)

Unit 10: Thermodynamics.

Quiz A reaction that releases heat is called?

ENTHALPY OF COMBUSTION ΔHc

IB Topics 5 & 15 PART 1: Heat and Calorimetry

PART 1: Heat and Calorimetry

Chemistry Quiz Ch 11 Section 11-1 & 11-2

Presentation transcript:

EXPERIMENT

RESULTS TIME (SECONDS) TEMPERATURE (OC) 20 5 35 10 55 15 50 MAXIMUM TEMPERATURE Question 1 - Calculate the energy released in your reaction. The density of water is 1 g/cm3 . The specific heat capacity of water is 4.2 J/g/°C. ANSWER DH = mcDT = 25 X 4.2 X (55 – 20) = 3675J = 3.675kJ

ANSWER The Zinc was in excess QUESTION 2 - Calculate the moles of zinc that you used. ANSWER REMEMBER From C2 (Additional Science) MOLES = MASS ÷ Mr ∴ MOLES = 2 ÷ 65 = 0.0308 mols of Zinc QUESTION 3 - The moles of CuSO4 solution that was used was 0.0125mols. Which substance Zn or CuSO4 was in excess? ANSWER The Zinc was in excess

ANSWER For Zinc = 3.675 ÷ 0.0308 = 119kJ/mol QUESTION 4 - Calculate the energy change in kJ/mol for the chemicals reacting ANSWER For Zinc = 3.675 ÷ 0.0308 = 119kJ/mol For CuSO4 = 3.675 ÷ 0.0125 = 294kJ/mol

a) Calculate the energy released in this reaction in kJ QUESTION -5g of zinc was added to 75cm3 of 1moldm-3 solution of CuSO4 solution. The temperature rose from 25 to 670C. a) Calculate the energy released in this reaction in kJ b) Calculate the moles of Zinc metals used c) The moles of CuSO4 used in this experiment was 0.075mols. Which substance Zinc or CuSO4 was in excess? d) Calculate the energy change in kJ/mol for the chemicals reacting ANSWER DH = mcDT = 75 x 4.2 x (67 – 25) = = 13230J = 13.23kJ b) Moles = Mass ÷ Mr = 5/65 = 0.0769 mols Zinc c)The zinc was in excess d) For Zinc = 13.23 ÷ 65 = 0.204kJ/mol For CuSO4 = 13.23 ÷ 0.075 = 176.4kJ/mol

REMEMBER METAL HYDROXIDE + ACID  SALT + WATER This is a neutralisation reaction

Question 1- Calculate the energy released in your reaction Question 1- Calculate the energy released in your reaction. The density of water is 1 g/cm3 . The specific heat capacity of water is 4.2 J/g/°C. ANSWER DH = m x c x DT = 50 x 4.2 x 28 = 5880J = 5.88kJ Question 2 -The number of moles of the acid used was 0.025mols. Calculate the energy released in the reaction in kJ/mol ANSWER 5.88/0.025 = 235kJ/mol

The energy released in the reaction in kJ QUESTION - 75cm3 of 0.5moldm-3 HCl reacts with 75cm3 of 0.5moldm-3 NaOH. The temperature rose from 20 to 420C. Calculate: The energy released in the reaction in kJ The moles of HCl used in this reaction is 0.0375mols. Calculate the energy released in the reaction in kJ/mol ANSWERS 13.86kJ 369.6kJ/mol

A BOMB CALORIMETER