MEASURING ENERGY FROM FUELS

Slides:



Advertisements
Similar presentations
25.3 Heat and Thermal Energy
Advertisements

Enthalpy of Solution (HSOLN)
Unit 1 PPA 3 ENTHALPY OF COMBUSTION. ENTHALPY OF COMBUSTION (Unit 1 PPA3) (1) Write the balanced equation for the enthalpy of combustion of ethanol. (2)Draw.
Enthalpy. Specific Heat Capacity Definition: The HEAT ENERGY required to raise the TEMPERATURE of 1kg of substance by 1 o C. e.g. for water C= 4.18kJ.
HEAT EQUATION (in Table T)
Aim: What is thermochemistry?. Law of Conservation of Energy In any chemical or physical process, energy is neither created nor destroyed. There are different.
Higher Chemistry Unit 1(b) Enthalpy of combustion.
Module 3 Lesson 4 – Calorimetry and enthalpy change of combustion.
Thermochemical Equations & Calorimetry
Calorimetry Heat of combustion Heat capacity Solution calorimetry Calibration factor Bomb calorimetry.
Enthalpy of Combustion
Enthalpy Calculations
Enthalpy of Combustion Calculations. Example Q. 4.6g of ethanol (C 2 H 5 OH) is burned. The energy released raised the temperature of 0.5kg of water by.
Unit 2 – Matter and Energy Mrs. Callender. Lesson Essential Question: What is Thermochemistry?
Specific Heat and Calculating Heat Absorbed
ENERGY CALCULATION PRACTICE UNIT 3. HOW MUCH ENERGY IS REQUIRED TO HEAT 200 GRAMS OF WATER FROM 25˚C TO 125˚C? HOW MUCH ENERGY IS RELEASED WHEN COOLING.
Combustion Reaction. Heat of Reaction (q) C 6 H 14(l) + O 2 (g)  CO 2 (g) + H 2 O (g) Energy required to break bonds Energy released as bonds form.
Energetics Topic 5.1 – 5.2 Topic 5.1 Exothermic and Endothermic Reactions.
Thermochemistry.
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.
1 Chapter 6 EnergyThermodynamics. 2 Energy is... n The ability to do work. n Conserved. n made of heat and work. n a state function. n independent of.
Energy in Reactions L.O: To understand how the energy released from different fuels can be measured Starter: do you remember burning biscuits from year.
Reaction Energy and Reaction Kinetics Chapter 17 Notes.
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.
Chapter 6: Enthalpy changes
Everyday Calorimetry. whenever we heat water, its like using a calorimeter calorimeters are used to compare quantities of different fuels that burn to.
Specific Heat Capacity Weather Unit – Science 10.
Measuring energy changes
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.
C3 3.1 Comparing the Energy Released by fuels Miss Chohan FSG.
Calculation of Enthalpy Values Using E = c m  T.
Chemistry 1011 TOPIC TEXT REFERENCE Thermochemistry
1. A 322 g sample of lead (specific heat = J/g o C) is placed into 264 g of water at 25 o C. If the system's final temperature is 46 o C, what was.
Energy Flow. Energy the ability to do work energy has no mass nor volume but is only detected by its effects thermochemistry studies energy changes during.
Comparing the Energy Released by fuels
IGCSE CHEMISTRY SECTION 4 LESSON 2. Content The iGCSE Chemistry course Section 1 Principles of Chemistry Section 2 Chemistry of the Elements Section 3.
Specific Heat Capacity. Specific Heat Capacity (kJ/kg/°C) The specific heat is the amount of heat (measured in kJ) per unit mass (measured in Kg) required.
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.
Section 10.2 The Flow of Energy 1.To convert between different energy units. 2.To understand the concept of heat capacity. 3.To solve problems using heat.
Calories from food Chapter 12. Calories Measurement of the energy content in a substance = heat Calorie = E require to raise the temperature of 1 gram.
Heat energy is measured in units called joules or calories. 1 calorie is the amount of heat energy needed to raise the temperature of 1.0 g (mL) of water.
Energy In Reactions Noadswood Science, 2013.
LO- Understand how enthalpy changes of combustion can be measured using calorimetry. Measuring Enthalpy Changes What can you remember from GCSE? The energy.
Thermochemistry.
Aim: What is thermochemistry?
Aim: What is thermochemistry?
Energy from burning.
Topic 5.2 Calculations of enthalpy changes
Klein Forest High School-Chemistry Jarrod G Collins, M.Ed.
Energy and Fossil Fuels
11.3 – NOTES Combustion.
UNIT 2 NATURE’S CHEMISTRY.
HC CHEMISTRY HC CHEMISTRY CHEMISTRY IN SOCIETY (C) CHEMICAL ENERGY.
4.3 Measuring enthalpy changes
Chemistry Do Now Directions: Use your notes to calculate the molar mass of each compound.   Au2(SO4)3 Fe(CN)3 C8H18.
Calorimetry C2.1 Thermochemistry 11 November 2018.
Unit 3 Science Investigation Skills
DO NOW: (on the front of your WS)
Thermochemistry.
Energy Content in Foods
Energetics Topic 5.1 – 5.2.
Units: g/mL, g/cm3.
Thermochemistry Lecture 1.
Enthalpy 18/04/2019.
Heating up • Relate a rise in the temperature of a body to an increase in internal energy • Show an understanding of the term thermal capacity Supplement.
Hydrocarbons and Heat Most hydrocarbons are used as fuels.
Quiz A reaction that releases heat is called?
ENTHALPY OF COMBUSTION ΔHc
Presentation transcript:

MEASURING ENERGY FROM FUELS CHEMISTRY N5 CHEMISTRY ENERGY FROM FUELS MEASURING ENERGY FROM FUELS

MEASURING ENERGY FROM FUELS CHEMISTRY N5 CHEMISTRY ENERGY FROM FUELS MEASURING ENERGY FROM FUELS After completing this topic you should be able to : Calculate the quantity of heat energy used to heat a given mass of water using the relationship Eh = cmΔT. Carry out an experiment to determine the heat energy Eh released from burning a fuel. State the measurements which are require to be made during the determination of the heat energy released from fuel experiment. Calculate Eh per gram of a fuel from experimental data.

MEASURING ENERGY FROM FUELS ENERGY RELEASED FROM FUELS Combustion of a fuel releases energy, i.e. it is an EXOTHERMIC REACTION. The unit for measuring energy is the JOULE (J). The unit is named after James Prescott Joule, the physicist who did a lot research on energy. A joule is a small quantity of energy. Often measurements of energy are given in kilojoules (kJ). To compare the quantity of energy released by different fuels the same mass of fuel must be burned in each experiment. The table shows the energy released when 1 gram of each fuel is burned. Energy released per gram (kJ g-1) Fuel How do chemists measure the energy released when 1 g of these fuels are burned? methane 55.7 butane 49.6 gasoline 48.3 methanol 22.7

Eh = c × m × ΔT MEASURING ENERGY RELEASED FROM A FUEL The energy released when a fuel burns can be used to heat water. When I absorb 418 kJ of energy from the flame, my temperature goes up by 1 oC. Facts about water: It requires 418 kJ of energy to raise 1 kilogram of water by 1 oC. This measurement is called the specific heat capacity of water. The symbol for this is the letter ‘c’. 1 cm3 of water has a mass = 1 g. Therefore, 1 kg of water has a volume = 1000 cm3 (1 litre). The energy required to heat a mass of water can be calculated using the following relationship: Eh = energy required to heat water in kJ. Eh = c × m × ΔT c = specific heat capacity of water = 418 kJ kg-1 oC-1. m = mass of water heated in kg. ΔT = temperature change of the water in oC.

Eh = c × m × ΔT Eh = c × m × ΔT = 418 × 05 × 16 Eh = 33.44 kJ Eh = energy required to heat water in kJ. c = specific heat capacity of water = 418 kJ kg-1 oC-1. m = mass of water in kg. ΔT = temperature rise of the water in oC. EXAMPLE Calculate the energy required to raise the temperature of 500 cm3 of water by 16 oC. Eh = c × m × ΔT c = 418 kJ kg-1 oC-1 = 418 × 05 × 16 m = 05 kg (500 cm3 = 500 g = 05 kg) ΔT = 16 oC Eh = 33.44 kJ Complete the HEATING WATER examples on page 2 of the MEASURING ENERGY FROM FUELS Examples Booklet.

MEASUREMENTS TO BE MADE EXPERIMENT: COMPARING FUELS AIM: To compare the energy released when 1 g of different alcohols is burned. ALCOHOLS: methanol, ethanol and propan-1-ol. thermometer MEASUREMENTS TO BE MADE copper can Mass of water in kg. Temperature of water before heating. Temperature of water after heating. Mass of burner at start. Mass of burner after heating water. 100 cm3 of water (0.1 kg) draught shield spirit burner fuel (alcohol) 100 cm3 of cold water is placed in the copper can and the temperature measured. The spirit burner is weighed before lighting. After lighting the burner, it is immediately placed under the can to heat the water. The water is stirred with the thermometer during heating. When the temperature of the water has risen by about 20 oC, the flame is extinguished, and the spirit burner weighed.

RESULTS ALCOHOL methanol ethanol propan-1-ol Mass of water / kg 0.1 Initial temperature of water / oC Final temperature of water / oC DT / oC Eh = c m DT (Energy transferred to the water) / kJ Initial mass of burner / g Final mass of burner / g Mass of alcohol burned / g Energy released per gram of alcohol / kJ g-1

CONCLUSION EVALUATION Look at the results of the experiment. Is there a pattern to the energy released when 1 g of methanol (CH3OH), ethanol (C2H5OH) and propan-1-ol (C3H7OH) is burned? EVALUATION Do you think your results are accurate? Do you think all the heat released from the burning fuels was transferred to the water? What are the limitations of the equipment? Can you suggest improvements to you could make to the experimental procedure? Complete the MEASURING ENERGY FROM FUELS examples on page 3 of the MEASURING ENERGY FROM FUELS Examples Booklet.