Exam Paper Flashcards
What is the null hypothesis for the investigation of orange star lichen abundance?
There is no significant difference in the abundance of orange star lichen based on the direction the wall faces.
What should be considered when planning an investigation?
Selecting appropriate equipment, techniques, and standards.
Why is it important to choose equipment with a smaller in-built error?
It increases the accuracy of measurements.
Which is more accurate for measuring 10 cm³: a 10 mL measuring cylinder or a 100 mL measuring cylinder?
A 10 mL measuring cylinder.
What are some factors to consider when choosing appropriate techniques for an investigation?
- What are you investigating? * What method(s) are you using? * Do you have the equipment available? * Do you have enough time? * Do you have the skills/knowledge?
Define qualitative data.
Qualitative data refers to the appearance or value of something, such as color or whether bubbles are produced.
Define quantitative data.
Quantitative data refers to numerical measurements, such as volumes and times measured.
What is a standard operating procedure (SOP)?
An established method used to carry out a routine activity to ensure consistent results.
List examples of standard operating procedures (SOPs).
- Titration * Handling of chemicals * Disposal of waste * Qualitative analytical tests * Preparing solutions.
Fill in the blank: Qualitative data is based on _______.
[the appearance or value of something]
Fill in the blank: Quantitative data is based on _______.
[numerical measurements]
True or False: A volumetric pipette is less accurate than a measuring cylinder.
False.
What is a hypothesis?
An idea that you can test using practical experiments
What are the two types of hypothesis?
- Null hypothesis
- Alternative hypothesis
What is another term often used for a hypothesis?
Educated guess
What is the structure of most hypothesis statements?
If/then statements
Fill in the blank: If the temperature of the reactants is _______ then the rate of reaction will increase.
increased
Fill in the blank: If more water is added to the soil then the plants will _______.
grow more
Fill in the blank: The growth of a crop is dependent on the type of _______.
fertiliser in the soil
What does a null hypothesis state?
There will be no relationship between variables
What is an example of a null hypothesis?
There is no relation between the temperature of the reactants and the rate of reaction
What are key features of a good hypothesis?
- Must be able to be tested scientifically
- Relate one dependent variable to one independent variable
How can observations lead to a hypothesis?
By making a statement that can be tested based on those observations
Fill in the blank: If a plant gets more sunlight then it will grow _______.
taller
What is an example of a hypothesis based on the growth of plants?
The height of a plant is dependent on the type of plant
What must you consider when testing a hypothesis about plant growth?
Other factors such as type of plant or minerals in the soil
What is the relationship between the size of molecules in a solution and their ability to pass through a membrane?
The bigger the molecules, the fewer molecules will pass through
Write an if/then statement for the following: When a 1 mol dm3 solution of acid was added to magnesium, it dissolved faster than in a 0.5 mol dm3 solution.
If a 1 mol dm3 solution of acid is added to magnesium, then it will dissolve faster than in a 0.5 mol dm3 solution.
Write an if/then statement for the following: A lamp in a circuit was dim with one cell and bright with three cells.
If there are three cells in the circuit, then the lamp will be very bright.
What is a risk assessment?
A risk assessment identifies hazards, evaluates the risks associated with those hazards, and determines ways to eliminate or control those risks.
Define ‘hazard’.
The equipment or substance that can cause harm, for example, hot plate or hydrochloric acid.
What is the difference between hazards and risks?
Hazards are the sources of potential harm, while risks are the harm that the hazard could cause and the chances of it happening.
What is an example of risk from using a hot plate?
The risk from using a hot plate is getting burnt.
What can hydrochloric acid cause as a risk?
The risk from using hydrochloric acid is skin corrosion or chemical burns.
What headings might be present in a risk assessment template?
- Severity of harm
- Likelihood of harm
- Control measures
- Procedures if harm occurs
List some common risks in laboratory settings.
- Chemical burns
- Eye damage or irritation
- Burns or fire
- Hearing damage
- Poisoning
- Inhalation of toxic fumes
- Cuts to skin from broken glassware
- Injury from dropping heavy equipment
- Slipping or tripping over spillages
What are some common control measures to mitigate risks?
- Wearing goggles or face shields
- Wearing a laboratory coat
- Wearing gloves
- Carrying out the experiment in a fume cupboard
- Using correct manual handling techniques
- Cleaning up broken glass or spillages as soon as they occur
What should you do in case of chemical burns?
Washing chemical contact with skin or eyes under running cold water.
What are emergency procedures for hearing damage?
Removal of affected person(s) to fresh air.
Fill in the blank: The risk assessment template includes the heading ‘Control ______’.
measures
True or False: A risk assessment is only concerned with identifying hazards.
False
Where can you find resources to help fill in a risk assessment form?
- http://www.hse.gov.uk/
- COSHH regulations
- CLEAPSS Hazards
What should you do if there is an emergency during an experiment?
Call emergency services for assistance.
