CHEMISTRY - HISTORY OF CHEMISTRY

chemistry mids

  • Explores the principle of conservation of mass in chemical reactions
  • Analyzes the reliability and accuracy of scientific measurements
  • Highlights the importance of peer review and replication in scientific research
  • Emphasizes the collaborative nature of scientific investigations

Here are the first 3 questions. Click “View all questions” to see the complete assessment.

Q1.

A chemist carries out a reaction in a sealed flask. The total mass before the reaction is 125 g. Why should the total mass after the reaction also be 125 g?

  1. A) Chemists assume that mass is conserved and use this principle to check findings.
  2. B) The mass of a sealed flask always increases during a reaction.
  3. C) Scientific results are accepted without comparison or verification.
  4. D) Every chemical reaction produces substances with identical properties.

Q2.

Three groups measure the boiling point of the same pure liquid. Group A obtains 79.9 °C, 80.0 °C and 80.1 °C; Group B obtains 76 °C, 80 °C and 84 °C; Group C takes only one reading of 80.0 °C. Which analysis best explains the confidence scientists should place in these outcomes?

  1. A) Group A provides the highest confidence because its repeated measurements are closely grouped.
  2. B) Group B provides the highest confidence because its measurements cover the widest range.
  3. C) All three groups provide equal confidence because each includes a reading of 80.0 °C.
  4. D) Group C provides the highest confidence because one reading eliminates uncertainty.

Q3.

A researcher reports that a new catalyst speeds up a reaction. Before accepting the claim, other chemists examine the method and repeat the experiment. What does this example show about science?

  1. A) Scientific knowledge is tested through peer review and reproducible evidence.
  2. B) Scientists must avoid questioning the work of other researchers.
  3. C) A claim becomes correct as soon as one scientist reports it.
  4. D) Chemical conclusions should be based mainly on personal opinion.

Q4.

The image compares repeated concentration measurements made with four instruments. Which instrument's result should be reported with the greatest confidence based on the displayed uncertainty?

Diagram for question 4: The image compares repeated concentration measurements made with four instruments. Which instrument's result…
  1. A) Instrument R
  2. B) Instrument P
  3. C) Instrument S
  4. D) Instrument Q

Q5.

In the image, which feature most clearly demonstrates that scientific investigation is a community process rather than the work of one person alone?

Diagram for question 5: In the image, which feature most clearly demonstrates that scientific investigation is a community process…
  1. A) The sample changes colour inside a beaker.
  2. B) Several researchers review the report and request revisions before publication.
  3. C) The experiment uses glass laboratory equipment.
  4. D) The lead researcher records observations in a notebook.

What this assessment covers

Concepts tested

  • Conservation of mass in chemical reactions
  • Reliability and accuracy in scientific measurements
  • Role of peer review in scientific validation
  • Importance of replication in experiments
  • Community aspect of scientific research

Question Mix

  • Easy questions included

Skills you build

  • Apply the concept of mass conservation to chemical reactions
  • Evaluate the reliability of experimental data
  • Interpret the significance of peer review in science
  • Assess the importance of repeated trials in experiments
  • Understand the collaborative nature of scientific work

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