Working Scientifically and Depth Study Flashcards
Define inquiry question
Inquiry Question is a question that focuses on a researchable issue whose answer takes the form of a claim that is supported by evidence, information, and reasoning
Define hypothesis
Hypothesis is a proposed explanation for a phenomenon, includes cause and effect language
Define aim
Aim is a statement outlining the purpose of the experiment
Define discussion
Discussion discusses whether the experiment addressed the hypothesis and aim
Discuss conclusion
Conclusion is a concise summary of ideas and results that have been forementioned and hence it never introduces any new ideas or results
Define validity
Validity refers to whether an experiment or investigation is in fact testing the set hypothesis and aims
Define reliability
Reliability refers to the idea that an experiment can be repeated many times and the average of the results from all the repeated experiments will be consistent
Define accuracy
Accuracy is the ability to obtain the correct measurement. To obtain accurate results, you must minimise systematic errors
Define precision
Precision is the ability to consistently obtain the same measurement. To obtain precise results, you must minimise random errors
Define systematic error
Systematic Error is an error that causes a consistent shift of the data in a singular direction
Define random error
Random Error is an error that is unpredictable and caused unknowingly and as the name suggests has no pattern
Define independent variable
Independent Variable is the variable that is changed
Define dependent variable
Dependent Variable is the variable that may be affected by the independent variable and is measured
Define controlled variable
Controlled Variables are the variables that are kept constant
Define qualitative variable
Qualitative Variables are the variables that are observed and cannot be measured
Define quantitative variable
Quantitative Variables are the variables that are measured
Define research question
A research question identifies the independent variable and dependent variable in an experiment and poses the relationship as a question
Compare inquiry question and research question
% difference
|experimental value - theoretical value| / theoretical value * 100
Outline the scientific method
- Develop a question
- Conduct research
- Formulate a hypothesis
- Design an investigation - test hypothesis
- Gather and analyse results
- Draw conclusions
Identify features of Metallic Bonding
Physical Properties:
High boiling and melting points –
strong electrostatic forces of attraction
High strength – strong electrostatic forces of attraction
Good conductors of heat and electricity – free moving (delocalised) charged particles
Malleable and Ductile – free moving charged particles
Identify features of Ionic Bonding
Physical Properties:
High boiling and melting points – strong electrostatic forces of attraction
Brittle – strong electrostatic forces of attraction and lattice structure – pressure causes misalignment hence brittle
Conducts electricity in the molten state – free moving (delocalised) charged particles
Identify features of Covalent Bonding
Physical Properties:
Low boiling and melting points – weak electrostatic forces of attraction
Inability to conduct electricity – no free moving (delocalised) electrons
Identify features of Covalent Network Bonding
Physical Properties:
High boiling and melting points – strong lattice structure
Inability to conduct electricity – no free moving (delocalised) electrons
Brittle – strong lattice structure
Define first ionisation energy
First ionisation energy is the minimum energy necessary to remove an electron in the gaseous state
Outline production of ethanol
Fermentation of sugar in starches of grains and the sugar - mainly in sugar cane and sugar beets
6 Step Process:
1. The organic matter is grounded
2. Water is added and heated to break the starch molecules
3. Enzymes, such as amylase, can be used as a catalyst
4. Glucose is formed
5. Yeast is added, producing ethanol
6. The ethanol is distilled and 5% gasoline is added to form pure ethanol
Outline production of biodiesel
Sourced from organic matter – Vegetable oils, yellow grease, used cooking oils, or animal fats
Biodiesel can be produced through:
- Esterification
- Transesterification
The removal of by-products, such as glycerin, is conducted through differences in chemical properties. The density of glycerin is greater than biodiesel
Define esterification
Esterification is the term that describes the process of reacting an alcohol with an acid to form ester and water
Define transesterification
Transesterification is a term that describes the process of converting fats and oils into biodiesel and glycerin (a by-product).
Outline production of petrol
Produced from crude oil extracted from underground reservoirs
At oil refineries, the crude is separated through fractional distillation
Additives are added to improve performance
Recall the interchangeable terms in the use of fuels
Petrol and Gasoline
Assess the suitability of ethanol
Fuel ethanol, known as E10 in Australia, is regular unleaded petrol blended with 9%-10% ethanol is suitable as it is safe, reliable and compatible with the majority of petrol powered engines.
However, fuel ethanol used in higher concentrations like E85, composed of 85% ethanol can only be used for purpose built vehicles.
Ethanol can’t also be used by planes, motorbikes or other small engines.
Assess the suitability of biodiesel
Biodiesel is compatible with diesel engines unless the biodiesel blend exceeds 20%
Economic benefits
Assess the suitability of petrol
Petrol is optimal for widespread light-duty transportation due to its high energy density and suitability for small engines, though it is unsustainable long-term being a non-renewable fossil fuel
Outline the thermal combustion equipment for ethanol
If the proportion of ethanol exceeds 10%, corrosion will occur in a conventional vehicle
Outline the thermal combustion equipment for biodiesel
As long as the blend does not exceed 20%, biodiesel is compatible with current technologies in diesel engines
Slight modifications to combat:
- Conflict with existing warranties
- Gelling in cold temperatures
- Storing issues
A diesel engine uses a compression-ignited injection system
Outline the injection systems
- Induction
- Compression / Spark
- Ignition
- Exhaust
Outline the spark-ignited injection system
Used for ethanol and petrol.
The fuel is mixed with air inducted into a cylinder during the fuel intake process. The piston compresses the air before a spark ignites it to cause combustion, pushing the piston down
Assess the sustainability of the use of ethanol
Produced from organic matter
Renewable resource
Assess the sustainability of the use of biodiesel
Produced from organic matter
Renewable resource
Assess the sustainability of petrol
Fossil fuel
Non-renewable resource
