Term
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Definition
| Release of energy, increases temperature of surroundings. |
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Term
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Definition
| Absorption of energy, decreases temperature of surroundings. |
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Term
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Definition
| energy being transferred in a chemical reaction under specific conditions. |
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Term
If ΔH is positive it is a ..............reaction.
If ΔH is negative it is a ..............reaction. |
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Definition
Positive = endothermic -more energy in products than reactants.
Negative = exothermic- more energy in reactants than products. |
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Term
| Define the molar enthalpy of combustion. |
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Definition
| The molar enthalpy of combustion of a substance is the quantity of heat energy released when 1 mole of a pure element or compound is burnt completely in oxygen under constant pressure. |
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Term
| Steps in writing equations for combustion reactions. |
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Definition
1. Write reactants and products
2. Balance Carbon
3. Balance Hydrogen
4. Balance Oxygen |
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Term
| Define the molar enthalpy of solution. |
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Definition
| The molar enthalpy of solution of a substance is the quantity of heat energy released or absorbed when 1 mole of the substance dissolves in sufficient water so that further dilution causes no further release or absorption of heat energy. |
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Term
| Define the molar enthalpy of neutralisation. |
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Definition
| The molar enthalpy of neutralisation is the quantity of heat energy released when 1 mole of hydrogen ions is transferred from an acid to a base in an acid-base reaction occurring in aqueous solution. |
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Term
| Equation for calculating the ΔH? |
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Definition
| ΔH = m(water) x ΔT(water) x Cp(water)/ (1000 x n) |
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Term
| What are the raw materials of fossil fuels? |
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Definition
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Term
| Through what chemical process are fossil fuels produced? |
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Definition
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Term
| What are the three fossil fuels? |
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Definition
| Crude oil, natural gas, coal |
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Term
| What are the advantages and disadvantages of coal as a fuel? |
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Definition
A: easily mines with low cost. Large reserves.
D: production of greenhouse gas, acid rain, non-renewable, hazardous mining, variable composition, harmful products of combustion. |
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Term
| What are the advantages and disadvantages of crude oil as a fuel? |
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Definition
A: large reserves, easily extracted and transported, produces a range of fuels.
D: non-renewable, variable composition, risky transport(oil spills, flammable), produces harmful gases. |
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Term
| What are the advantages and disadvantages of natural gas as a fuel? |
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Definition
A: easily extracted purified and distributed, combusts cleanly, high energy density.
D: harmful combustion products, non-renewable, flammable, less common |
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Term
| What are the raw materials and chemical process that produce ethanol? |
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Definition
| Sugar, grain crops, Ag waste by fermentation. |
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Term
| What are the advantaged and disadvantages of ethanol as a fuel? |
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Definition
A: high oxygen - likely to completely combust, only produces CO2 and water, renewable.
D: poor fuel economy, use of fossil fuels in manufacture, uses up agricultural land, not readily available. |
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Term
| Name two exothermic reactions. |
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Definition
| Combustion and respiration |
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Term
| Name an exothermic reaction. |
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Definition
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Term
| What are the advantages and disadvantages of biofuel? |
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Definition
A: Renewable and biodegradable. Fewer harmful emissions. Improved engine lubrication.
D:blends can damage engine, decreased fuel economy, can congeal at low temp, expensive, fossil fuels used in manufacture, not widely available, emission contribute to photochemical smog. |
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Term
| Equation for the complete combustion of fuels. |
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Definition
C6H12 + 9O2 = 6CO2 + 6H2O
ΔH = -3616 kJ/mol |
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