This experiment compares the way that seawater and distilled water absorb carbon dioxide from the air.
Teaching Tips
Positives
The resource offers teachers several methods for graphing the data collected during the experiment.
The resource includes a diagram and a photo of the setup.
Additional Prerequisites
Students should be familiar with the pH scale.
Teachers will need a big transparent basin or a big aquarium, 2 500 ml-beakers, 2 pH Meters, an aquarium pump, plastic tubing, and 2 airstones with regulator valves, seawater, distilled water, 5 candles, a box of matches, and a stopwatch.
Teachers can make a seawater solution by combining sea salt and water.
Differentiation
Chemistry classes could discuss how a body of water's alkalinity can either help or harm it when faced with higher carbon dioxide levels in the atmosphere.
Teachers may want to show students this Khan Academy video on ocean acidification and discuss how the alkalinity of ocean water normally allows it to be a carbon sink, but how the dramatic increase in carbon dioxide emissions has impacted the acidity of the ocean water.
Scientist Notes
This resource is a lesson plan in which the impact of carbon dioxide on seawater and distilled water are tested. The lesson plan is well organized, although it requires some materials that are not commonly available (pumps and pH sensors). There is not a lot of context and connection to climate change included, but it is a good self-contained lesson plan. This resource is recommended for teaching.
Standards
Next Generation Science Standards (NGSS)
ESS2: Earth's Systems
HS-ESS2-5 Plan and conduct an investigation of the properties of water and its effects on Earth materials and surface processes.
HS-ESS2-6 Develop a quantitative model to describe the cycling of carbon among the hydrosphere, atmosphere, geosphere, and biosphere.
ESS3: Earth and Human Activity
HS-ESS3-5 Analyze geoscience data and the results from global climate models to make an evidence-based forecast of the current rate of global or regional climate change and associated future impacts to Earth systems.
PS1: Matter and its Interactions
MS-PS1-2 Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
