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Ch. 2 - Water and Carbon: The Chemical Basis of Life
Freeman - Biological Science 8th Edition
Freeman8th EditionBiological ScienceISBN: 9780138276263당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Freeman 8th EditionCh. 2 - Water and Carbon: The Chemical Basis of Life문제 12
2장, 문제 12

The current average pH of our oceans is 8.1. What is the concentration of protons in the oceans? How has the proton concentration changed in our oceans when compared to before the industrial revolution, when the average pH was 8.2? Express this change as a percentage increase.

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1
Calculate the concentration of protons (H+) in the ocean for the current average pH of 8.1 using the formula: \( [H^+] = 10^{-pH} \).
Calculate the concentration of protons (H+) in the ocean for the pH before the industrial revolution, which was 8.2, using the same formula: \( [H^+] = 10^{-pH} \).
Compare the two proton concentrations to find the absolute change in proton concentration. This can be done by subtracting the proton concentration at pH 8.2 from the proton concentration at pH 8.1.
To find the percentage increase in proton concentration, use the formula: \( \text{Percentage Increase} = \left( \frac{\text{New Concentration} - \text{Old Concentration}}{\text{Old Concentration}} \right) \times 100\% \).
Interpret the results to understand how the proton concentration in the oceans has changed due to changes in pH levels, reflecting on the impact of acidification.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

pH Scale

The pH scale measures the acidity or alkalinity of a solution, ranging from 0 to 14. A pH of 7 is neutral, while values below 7 indicate acidity and above 7 indicate alkalinity. Each whole number change on the pH scale represents a tenfold change in hydrogen ion concentration, meaning that a decrease in pH corresponds to an increase in proton concentration.
추천 영상:
11:05
pH Scale

Proton Concentration

Proton concentration in a solution is directly related to its pH value. The formula to calculate proton concentration ([H+]) from pH is [H+] = 10^(-pH). Therefore, a lower pH indicates a higher concentration of protons, which is crucial for understanding changes in ocean chemistry over time, particularly in relation to ocean acidification.
추천 영상:
04:51
Concentration Gradients and Diffusion

Ocean Acidification

Ocean acidification refers to the decrease in pH levels of ocean waters due to increased carbon dioxide (CO2) emissions. Since the industrial revolution, the absorption of CO2 by oceans has led to a measurable drop in pH, resulting in higher proton concentrations. This change can have significant impacts on marine life, particularly organisms that rely on calcium carbonate for their shells and skeletons.
추천 영상:
03:57
Seasonal Turnover & Ocean Upwelling
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교과서 질문

Consider the reaction between carbon dioxide and water to form carbonic acid (CH2O3):


CO2(𝑔)+H2O(𝑙)⇌CH2O3(𝑎𝑞)


In the ocean, carbonic acid immediately dissociates to form a proton and bicarbonate ion, as follows:


CH2O3(𝑎𝑞)⇌CHO3−(𝑎𝑞)+H+(𝑎𝑞)


As atmospheric CO2 increases, the ocean absorbs more of the gas. Would this sequence of reactions be driven to the left or the right? How would this affect the pH of the ocean?

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교과서 질문

When H2 and CO2 react, acetic acid can be formed spontaneously while the production of formaldehyde requires an input of energy. Which of these conclusions can be drawn from this observation?

a. More heat is released when formaldehyde is produced compared to the production of acetic acid.

b. Compared to the reactants that it is formed from, formaldehyde has more potential energy than does acetic acid.

c. Entropy decreases when acetic acid is produced and increases when formaldehyde is produced.

d. Only acetic acid could be produced under conditions that existed in early Earth.

1994
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교과서 질문

From what you have learned about water, why do coastal regions tend to have milder climates with cooler summers and warmer winters than do inland areas at the same latitude?

2435
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