← Ocean Acidification: pH and the Ocean's Balance
Flashcards
Ocean Acidification: pH and the Ocean's Balance
Generated from the original open resource by NOAA. Built only from the resource — nothing invented. Free, no login.
Ocean Acidification: pH and the Ocean's Balance
| Front | Back |
|---|---|
| What is the essential question of this lesson? | What does a shift in the ocean's pH mean for marine organisms? |
| What is pH? | A scale (0-14) that measures how acidic or basic a liquid is; one way scientists measure ocean acidification. |
| What is an acid? | A substance below 7 on the pH scale; usually sour, stings if touched, and reacts with or degrades metals. Strongest acid = 0. |
| What is a base? | A substance above 7 on the pH scale; bitter, slippery if touched, and dissolves fats and oils. Strongest base = 14. |
| What does a pH of 7 mean? | Neutral — neither an acid nor a base. |
| Why is carbon dioxide (CO2) important to ocean acidification? | CO2 is an "acid gas" — about a quarter of CO2 emitted from burning fossil fuels ends up in the ocean, causing it to become more acidic (lower pH). |
| What is the historical change in ocean pH? | The ocean's pH has dropped from 8.1 about 100 years ago to 8.0 today. |
| Why does a small pH change matter, even though it seems tiny? | pH is measured on a scale where small changes represent exponentially larger shifts in chemical balance ("simplifying models" value). |
| What is acidosis? | A human health condition caused by just a 0.05 decrease in blood pH (from healthy 7.4), causing headaches, confusion, tiredness, tremors, and impaired brain function. |
| How does ocean acidification affect marine organisms like clownfish? | Scientists have observed effects similar to acidosis — for example, clownfish may become confused and swim toward predators in more acidic water. |
| What is the causal chain linking fossil fuels to ocean acidification? | Burning fossil fuels emits CO2 → ocean absorbs CO2 → CO2 is an acid gas → ocean becomes more acidic → a small pH decrease (0.1 units) can shift marine organisms from healthy to unhealthy. |
| What human activities contribute to CO2 emissions affecting the ocean? | Driving cars, boats, planes, trains; using electricity in homes; deforestation (removing trees that store CO2). |
| Why does deforestation contribute to ocean acidification? | Trees hold CO2 in their leaves; removing them prevents this storage, allowing more CO2 to enter the atmosphere and eventually the ocean. |
| What is the "Interconnected" value in this lesson? | Marine organisms and humans both maintain a delicate pH balance to remain healthy. |
| What are some individual solutions to reduce CO2 emissions? | Turning off lights when leaving a room; unplugging "vampire electronics" like chargers and computers. |
| What are some community-scale solutions to reduce CO2 emissions? | Hosting events to make homes more energy efficient; using public transportation, biking, or walking; advocating for better public transit and bike lanes. |
| What is the approximate pH of the ocean today compared to human blood? | Ocean pH = 8.0 (was 8.1); human blood pH = 7.4. |
| What is the pH of common household acids like vinegar and lemon? | Vinegar ≈ 2.8; lemon ≈ 2.3 — both strong acids. |
Original licensed under Public Domain. This teaching material is provided free by OER.ai.