3.1.1 Planning Experiments

• The problem or hypothesis should outline the relationship between the independent, dependent, and control
• Match the variable type with its role in an experiment:

  Temperature ↔️ Independent variable

  Reaction Rate ↔️ Dependent variable

  Reactant concentrations ↔️ Control variable
• In an experiment studying the effect of water amount on plant growth, what is the independent variable?

  Amount of water
• Steps in planning an experiment as outlined in the material

  1️⃣ Define the problem/hypothesis

  2️⃣ Outline variables

  3️⃣ Select equipment

  4️⃣ Design experimental procedures

  5️⃣ Develop data collection methods

  6️⃣ Outline safety procedures

  7️⃣ Plan analysis and evaluation
• Increasing the temperature will decrease the rate of a chemical reaction according to the hypothesis

  False
• The dependent variable is measured to see how it is affected by the independent
• Match the factor to consider when selecting equipment with its importance:

  Accuracy ↔️ Sufficient precision in measurement

  Range ↔️ Ability to measure expected values

  Sensitivity ↔️ Detection of small changes

  Safety ↔️ Prevention of injury
• The problem or hypothesis should outline the relationship between the independent, dependent, and control
• When selecting equipment, accuracy is crucial because it minimizes measurement errors
• Equipment must be precise to minimize errors
• What should you check when preparing materials for an experiment?

  Calibration
• What materials are needed to investigate the effect of acid concentration on reaction rate?

  Acids, cylinder, stopwatch
• What is calculated after repeating measurements in an experiment?

  Average
• What protective equipment should be used when handling chemicals?

  Gloves, goggles, lab coat
• Match the variable type with its definition:

  Independent Variable ↔️ Variable you change

  Dependent Variable ↔️ Variable you measure

  Control Variables ↔️ Variables you keep constant
• In an experiment studying the effect of water amount on plant growth, the dependent variable is the height of plant growth.
• What is the primary goal of using equipment safely in an experiment?

  Prevent injury
• What should be checked when preparing materials for an experiment?

  Calibration, purity, compatibility
• Why are tables used in data collection?

  To organize measurements
• Match the hazard with its safety measure:

  Chemicals ↔️ Handle with care

  Heat ↔️ Use tongs or gloves

  Sharp Instruments ↔️ Cut away from body

  Electricity ↔️ Ensure connections are secure
• What is assessed during the evaluation phase of an experiment?

  Validity and reliability
• What is an example of a problem in experimental design?

  How does temperature affect reaction rate?
• What is the definition of an independent variable?

  The variable you change
• Control variables must be kept constant to prevent confounding effects on the dependent variable
• Choosing the right equipment ensures the experiment can be carried out effectively and the results are reliable
• Control variables ensure that changes in the dependent variable are solely due to the independent variable
• What is one factor to consider when selecting equipment for an experiment?

  Accuracy
• Steps to follow when designing experimental procedures

  1️⃣ Prepare Materials

  2️⃣ Set Up

  3️⃣ Carry Out Experiment

  4️⃣ Record Data
• Documenting observations is essential while conducting the experiment.
• Match the data collection method with its purpose:

  Use tables to organize data ↔️ Provides a clear structure

  Repeat measurements ↔️ Minimizes random errors
• Calibrated instruments ensure accuracy in measurements.
• Grounded equipment is necessary when working with electricity.
• The independent variable is manipulated to test its effect on the dependent variable
• The equipment should cover the entire range of possible values for the dependent variable
• Steps in designing experimental procedures

  1️⃣ Prepare Materials

  2️⃣ Set Up

  3️⃣ Carry Out Experiment
• Data should be recorded accurately and consistently during an experiment.
• Maintaining consistent units is essential in data collection.
• During data analysis, statistical measures like mean, median, and standard deviation are calculated to identify relationships
• Why is ease of use important when selecting equipment for an experiment?

  To minimize errors
• In an experiment studying the effect of water amount on plant growth, what is the control variable?

  Type of soil