Badly worded question? (chemical vs physical changes)

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In summary: Aerosols are created when something, like smoke from a fire, is broken down into tiny airborne particles. These particles can be made from natural substances, like dust, pollen, and volcanic ash, or from manmade substances, like automobile exhaust and industrial pollutants.
  • #1
sp3sp2sp
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Homework Statement


The question states: "Which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions?"
Then the question lists 6 different scenarios and I have to sort them into either "chemical reaction" or "physical change".
Two of the the scenarios are:
"human activities such as the combustion of fossil fuels has increased the levels of greenhouse gases."
"human activities such as the combustion of fossil fuels generate aerosols."

Homework Equations

The Attempt at a Solution


I realize that combustion is always a chemical change, but when they list two effects of it, that's what confusing me. Is the question asking whether the combustion of fossil fuels is chemical or physical, or is it asking whether increased greenhouse gases and the generation of aerosols are chemical or physical? thanks
 
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  • #2
sp3sp2sp said:

Homework Statement


The question states: "Which of following changes that affect the composition of our atmosphere involve physical changes and which involve chemical reactions?"
Then the question lists 6 different scenarios and I have to sort them into either "chemical reaction" or "physical change".
Two of the the scenarios are:
"human activities such as the combustion of fossil fuels has increased the levels of greenhouse gases."
"human activities such as the combustion of fossil fuels generate aerosols."

Homework Equations

The Attempt at a Solution


I realize that combustion is always a chemical change, but when they list two effects of it, that's what confusing me. Is the question asking whether the combustion of fossil fuels is chemical or physical, or is it asking whether increased greenhouse gases and the generation of aerosols are chemical or physical? thanks
Do you have some scenarios for which both answers would be true? If so, could you list them them in both categories and designate the part of the scenario that applies to each category?
 
  • #3
Increase in greenhouse gases is a physical change but those gases come from the burning of fossil fuels. Thats why I think the question is ambiguous isn't it? I don't have option to choose both categories
 
  • #4
sp3sp2sp said:
Increase in greenhouse gases is a physical change but those gases come from the burning of fossil fuels. Thats why I think the question is ambiguous isn't it? I don't have option to choose both categories
Maybe you could look at the processes involved. Can you write chemical formulae for production of greenhouse gases? How about for aerosols?
 
  • #5
I agree, question is ambiguous. It would be a quite nice open question, checking your understanding of the processes involved, but if you are expected to classify it just confuses.
 
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  • #6
But just to make sure I am correct that it actually is badly worded, isn't it because:

Burning of fossil fuels is a chemical change (combustion).
Increase in greenhouse gases is a physical change (simply an increase in V of gases)

Is this correct?
 
  • #7
Yes, more or less. I would prefer to speak about change of amount and concentration of greenhouses than about change in their volume (even if technically that's correct).
 
  • #8
It is a badly worded question but I would just answer chemical for the first and physical for the second.

We aren't adding C02 to the atmosphere. We are mostly taking oxygen out, chemically altering it by reacting it with carbon and putting it back.

Edit: Actually we are releasing CO2 by causing chalk/calcium carbonate to be dissolved at an increasing rate.
 
  • #9
CWatters said:
We aren't adding C02 to the atmosphere. We are mostly taking oxygen out, chemically altering it by reacting it with carbon and putting it back.

Edit: Actually we are releasing CO2 by causing chalk/calcium carbonate to be dissolved at an increasing rate.

Can you elaborate? I have a hard time trying to understand what you mean.

By my book we are removing the O2 and replacing it with an equimolar amount of CO2. As in effect the amount of CO2 in atmosphere grows I see no problem with using the word "adding".
 
  • #10
Incorrect! I answered that
"human activities such as the combustion of fossil fuels has increased the levels of greenhouse gases." = chemical change.
"human activities such as the combustion of fossil fuels generate aerosols." = physical change
=wrong. (doesnt specify whether one or both are wrong)

edit: sorry it actually gave feedback..says that "1 out of the 5 items were sorted incorrectly"
 
  • #11

Related to Badly worded question? (chemical vs physical changes)

1. What is the difference between a chemical and physical change?

A chemical change involves a chemical reaction where new substances are formed, while a physical change involves a change in appearance or state of matter without the formation of new substances.

2. How can you determine if a change is chemical or physical?

One way to determine if a change is chemical or physical is to observe if there is a change in the chemical composition of the substances involved. A chemical change will result in the formation of new substances with different properties, while a physical change will only result in a change of appearance or state of matter.

3. What are some examples of chemical and physical changes?

Examples of chemical changes include burning wood, rusting of iron, and cooking an egg. Examples of physical changes include melting ice, boiling water, and cutting paper.

4. Can a physical change also involve a change in chemical composition?

No, a physical change does not involve a change in chemical composition. However, sometimes a physical change can be a precursor to a chemical change, where the physical change allows for easier access of reactants for a chemical reaction to occur.

5. How do I know if a question is badly worded when discussing chemical and physical changes?

A question may be considered badly worded if it is unclear or confusing in its meaning or intent. It is important to use precise and accurate language when discussing scientific concepts to avoid any misunderstandings or incorrect interpretations.

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