Working Scientifically and Depth Study

Question 1

Define inquiry question

Answer 1

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

Question 2

Define hypothesis

Answer 2

Hypothesis is a proposed explanation for a phenomenon, includes cause and effect language

Question 3

Define aim

Answer 3

Aim is a statement outlining the purpose of the experiment

Question 4

Define discussion

Answer 4

Discussion discusses whether the experiment addressed the hypothesis and aim

Question 5

Discuss conclusion

Answer 5

Conclusion is a concise summary of ideas and results that have been forementioned and hence it never introduces any new ideas or results

Question 6

Define validity

Answer 6

Validity refers to whether an experiment or investigation is in fact testing the set hypothesis and aims

Question 7

Define reliability

Answer 7

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

Question 8

Define accuracy

Answer 8

Accuracy is the ability to obtain the correct measurement. To obtain accurate results, you must minimise systematic errors

Question 9

Define precision

Answer 9

Precision is the ability to consistently obtain the same measurement. To obtain precise results, you must minimise random errors

Question 10

Define systematic error

Answer 10

Systematic Error is an error that causes a consistent shift of the data in a singular direction

Question 11

Define random error

Answer 11

Random Error is an error that is unpredictable and caused unknowingly and as the name suggests has no pattern

Question 12

Define independent variable

Answer 12

Independent Variable is the variable that is changed

Question 13

Define dependent variable

Answer 13

Dependent Variable is the variable that may be affected by the independent variable and is measured

Question 14

Define controlled variable

Answer 14

Controlled Variables are the variables that are kept constant

Question 15

Define qualitative variable

Answer 15

Qualitative Variables are the variables that are observed and cannot be measured

Question 16

Define quantitative variable

Answer 16

Quantitative Variables are the variables that are measured

Question 17

Define research question

Answer 17

A research question identifies the independent variable and dependent variable in an experiment and poses the relationship as a question

Question 18

Compare inquiry question and research question

Question 19

% difference

Answer 19

|experimental value - theoretical value| / theoretical value * 100

Question 20

Outline the scientific method

Answer 20

1. Develop a question
2. Conduct research
3. Formulate a hypothesis
4. Design an investigation - test hypothesis
5. Gather and analyse results
6. Draw conclusions

Question 21

Identify features of Metallic Bonding

Answer 21

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

Question 22

Identify features of Ionic Bonding

Answer 22

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

Question 23

Identify features of Covalent Bonding

Answer 23

Physical Properties:
Low boiling and melting points – weak electrostatic forces of attraction

Inability to conduct electricity – no free moving (delocalised) electrons

Question 24

Identify features of Covalent Network Bonding

Answer 24

Physical Properties:
High boiling and melting points – strong lattice structure

Inability to conduct electricity – no free moving (delocalised) electrons

Brittle – strong lattice structure

Question 25

Define first ionisation energy

Answer 25

First ionisation energy is the minimum energy necessary to remove an electron in the gaseous state

Question 26

Outline production of ethanol

Answer 26

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

Question 27

Outline production of biodiesel

Answer 27

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

Question 28

Define esterification

Answer 28

Esterification is the term that describes the process of reacting an alcohol with an acid to form ester and water

Question 29

Define transesterification

Answer 29

Transesterification is a term that describes the process of converting fats and oils into biodiesel and glycerin (a by-product).

Question 30

Outline production of petrol

Answer 30

Produced from crude oil extracted from underground reservoirs

At oil refineries, the crude is separated through fractional distillation

Additives are added to improve performance

Question 31

Recall the interchangeable terms in the use of fuels

Answer 31

Petrol and Gasoline

Question 32

Assess the suitability of ethanol

Answer 32

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.

Question 33

Assess the suitability of biodiesel

Answer 33

Biodiesel is compatible with diesel engines unless the biodiesel blend exceeds 20%
Economic benefits

Question 34

Assess the suitability of petrol

Answer 34

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

Question 35

Outline the thermal combustion equipment for ethanol

Answer 35

If the proportion of ethanol exceeds 10%, corrosion will occur in a conventional vehicle

Question 36

Outline the thermal combustion equipment for biodiesel

Answer 36

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

Question 37

Outline the injection systems

Answer 37

• Induction
• Compression / Spark
• Ignition
• Exhaust

Question 38

Outline the spark-ignited injection system

Answer 38

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

Question 39

Assess the sustainability of the use of ethanol

Answer 39

Produced from organic matter
Renewable resource

Question 40

Assess the sustainability of the use of biodiesel

Answer 40

Produced from organic matter
Renewable resource

Question 41

Assess the sustainability of petrol

Answer 41

Fossil fuel
Non-renewable resource