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• What is a prediction using scientific knowledge called?

  Hypothesis
• What does the term accuracy mean in scientific measurements?

  How close the measurement is to the true value
• What are variables in an experiment?

  Factors that can affect the outcome
• What is an independent variable?

  A factor changed to see its effect
• What is a dependent variable?

  A factor that is measured or observed
• What is a control variable?

  A factor kept constant throughout the experiment
• What is oxidation in chemical terms?

  The loss of electrons or increase in oxidation state
• What is reduction in chemical terms?

  The gain of electrons or decrease in oxidation state
• What is a redox reaction?

  A reaction where some atoms are oxidised and others reduced
• How can the percentage of iron in iron tablets be found?

  1. Prepare a standard solution of iron (II) using the tablets and sulfuric acid.
  2. Titrate a set volume of this iron(II) solution against KMnO4.
  3. Repeat until concordant results are obtained and calculate a mean titre.
  4. Calculate the moles of KMnO4 that reacted.
  5. Use the ratio in the chemical equation to find moles of iron that reacted.
  6. Calculate the percentage mass of iron using the mass in the standard solution.
• Describe how to make a standard solution of acidified iron(II) sulfate.

  1. Grind up iron tablets and measure total mass.
  2. Add powdered tablets to a conical flask and reweigh the weighing boat.
  3. Add 50cm³ of sulfuric acid to dissolve the iron and shake well.
  4. Filter the solution into a volumetric flask without disturbing the residue.
  5. Rinse the filter paper with distilled water and fill the volumetric flask to the graduation mark.
• Write an equation for the redox reaction between iron(II) ions and manganate(VII) ions.

  5Fe$^{2+}$ + MnO$_{4}^{-}$ + 8H$^{+}$ → 5Fe$^{3+}$ + Mn$^{2+}$ + 4H$_{2}O$
• What method should be used to find the mass of solute when making a standard solution?

  Weighing-by-difference method
• Why is an indicator not required in the titration between Fe$^{2+}$ and MnO$_{4}^{-}$?


  KMnO$_{4}$ is self-indicating; first pale pink colour
• What are concordant results in a titration?

  Titres that are within 0.1 cm³ of each other
• What are three possible sources of error in the iron titration experiment?

  • Iron may not completely dissolve; warming may help.
  • Some iron may not transfer between containers; take washings.
  • The end point may be hard to see; use a white tile underneath.
• What equation links concentration, moles, and volume?

  Moles = volume x concentration
• What equation links mass, molecular mass, and number of moles?

  Mass (g) = molecular mass x mole
• What is primary research?

  A new set of data collected
• Give two examples of primary research.

  Surveys and experiments
• What is secondary research?

  Data from other studies used for conclusions
• What is the difference between qualitative and quantitative data?

  Qualitative - descriptions; Quantitative - numerical data
• Online and offline resources can be used for what?

  Research
• Describe the Vancouver referencing system.

  • Full references are numbered at the end of a document.
  • Numbers linked to the appropriate reference in order of appearance.
  • Example: 1. Author (year), title.
  • Additional info may include page number, volume/issue number, web address, or date of access.
• Describe the Parenthetical (Harvard) referencing system.

  • Author's name and date in brackets at an appropriate point in the text.
  • Example: Universal indicator can be used to measure pH (author, date).
  • References listed at the end in alphabetical order without numbers.
  • If more than 3 authors, write first name followed by ‘et al.’.
• What is the general reference format for books?

  Author (year), Title, edition, publisher’s location, publisher
• What is the general reference format for journal articles?

  Author (year), ‘Article title’, Journal title, volume, issue, pp. xxx-xxx
• What is the general reference format for websites?

  Author (year), Title. [online] Last accessed date: URL