Tutor profile: Sean D.
Subject: Environmental Science
Explain how positive feedback loops could exacerbate the effects of climate change? Provide an example in your explanation.
A positive feedback loop takes place when the product of a reaction results in an increase of that reaction. As a result, positive feedback loops tend to amplify change. Let's consider ocean warming as an example of how positive feedback loops could amplify climatic changes. In this example, the initial reaction is an increase in atmospheric CO2 brought on by the burning of fossil fuels, transportation, and other industrial processes. Due to the the greenhouse effect, an increase in atmospheric CO2 will heighten the warming potential of the atmosphere, increasing the atmospheric temperature in turn. As air temperatures warm, so will ocean temperatures. The solubility of CO2 in water decreases as water temperature increases. Therefore, as water warms it will release CO2 into the atmosphere. In this instance, an initial increase in CO2 from greenhouse gas emissions could lead to changes which further add CO2 into the atmosphere.
Compare the strength of intermolecular forces between a substance with a high boiling point and a substance with a lower boiling point.
The boiling point of a substance is directly related to the strength of its intermolecular forces (attractive forces between molecules of a substance). As heat is applied to any liquid the average kinetic energy (KE) of its molecules will increase until it arrives at the boiling point. As the KE of molecules increases, intermolecular forces (IMFs) are overcome, and weaken. Substances with weak IMFs, need very little KE to overcome the attractive forces between molecules. As a result they will have low boiling points. In contrast, molecules need much more KE to overcome the forces of attraction in substances with strong IMFs. More heat will be needed to overcome the stronger IMFs, and boiling will occur at a higher temperature. Therefore, A substance with a substance with a high boiling point will likely have stronger IMFs than a substance with a lower boiling point.
Subject: Basic Chemistry
Describe what "moles" represent. In your answer, explain why they are useful for chemists.
Moles are a standard unit representing an amount of a substance. We know that a standard dozen refers to twelve of something––could be slices of bread, eggs, or dollars. Moles, in a similar way, refer to 6.02x10^23 particles of a given substance––the identity of the materials does not matter. By using moles, chemists can make the subatomic world easier to comprehend and manage. Chemists can readily convert between weight, number of particles, and the number of moles in a substance, allowing for precision and predictability in chemical equations and experimentation.
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