Experimental Design

Vocabulary flashcards covering core scientific experimental design concepts and specific observations from the magnesium carbonate reaction investigation.

Independent variable

The variable deliberately changed by the scientist.

Dependent variable

The variable measured during an experiment.

Controlled variable

A variable kept the same to make the experiment fair.

Hypothesis

A prediction about what will happen, supported by a reason.

Fair test

An experiment where only the independent variable is changed.

Multiple trials

Repeated tests carried out to identify unusual results, reduce errors and improve reliability.

Magnesium carbonate experiment: Equipment strength

The equipment was tightly sealed, so no $CO_2$ escaped.

Magnesium carbonate experiment: Controlled acid volume

The volume of hydrochloric acid was kept at $100\text{ mL}$.

Magnesium carbonate experiment: Weaknesses

Only one trial was performed for each test, and acid concentration and initial temperature were not controlled.

Magnesium carbonate investigation: Independent variable

Surface area of the solid reactant.

Magnesium carbonate investigation: Dependent variable

Rate of reaction with the acid.

Magnesium carbonate experiment: Acid used

Hydrochloric acid.

Surface-area experiment hypothesis

If surface area increases, the rate of reaction will increase.

Surface area effect on reaction rate

Increasing surface area increases the reaction rate because more particles are exposed, allowing more collisions.

Magnesium carbonate experiment: Surface area comparison tests

Tests 1 and 2, according to the source's explanation.

Exothermic reaction (from temperature data)

A reaction indicated when the final temperature is higher than the initial temperature.