Common Misconceptions
Students come with their own set of knowledge and ideas, which, may often times be mere hypothetical conclusions with no basis in scientific theory. Listed below are some of the more commonly found misconceptions in organic chemistry that students may hold. Please note that this list is in no way a comprehensive summary of all the possible misconceptions in organic chemistry.
1. Students often think that the word "organic" means natural.
The word "organic" is often associated with being natural, which stems from the notion of organic produce grown naturally without the use of pesticides.
Clarification: In chemistry, the term "organic" means carbon-based. Thus, organic chemistry is the study of carbon-based compounds, which includes both natural and synthetic compounds.
An activity to help overcome this misconception is to ask students "What do you think of when you hear the word 'organic'? ". Write down all the students' thoughts on the board and point out how a single word can mean different things to different people. To clarify, compounds are classified as organic based on whether they contain carbon, not whether it is naturally found or synthetic.
Clarification: In chemistry, the term "organic" means carbon-based. Thus, organic chemistry is the study of carbon-based compounds, which includes both natural and synthetic compounds.
An activity to help overcome this misconception is to ask students "What do you think of when you hear the word 'organic'? ". Write down all the students' thoughts on the board and point out how a single word can mean different things to different people. To clarify, compounds are classified as organic based on whether they contain carbon, not whether it is naturally found or synthetic.
2. Students often think that all compounds found in living organisms are organic.
There
are many compounds essential to life that are not considered to be organic.
Examples include certain salts and minerals. Remember, the term organic means carbon containing.
Carboon dioxide (CO2) is a carbon containing compound used in respiration/photosynthesis but it is not considered an organic
compound. Therefore, Carboon dioxide (CO2) and carbon monoxide (CO) are considered to be exceptions to the definition of organic compounds.
An activity you can do with you students where you show students a number of different common organic and inorganic compounds and ask: Is this compound organic or inorganic? How do we know?
An activity you can do with you students where you show students a number of different common organic and inorganic compounds and ask: Is this compound organic or inorganic? How do we know?
- C6H12O6 – glucose (organic)
- C5H4N4O3 – uric acid (organic)
- H2O – water (inorganic)
- NaCl – salt (inorganic)
- CH4 – methane (organic)
3. Students often think that the prefix hydro- in the term hydrocarbons means they contain water.
Clarification: The prefix hydro- refers to hydrogen. Therefore, hydrocarbons are defined as compounds that contain only carbon and hydrogen atoms.
4. Students often think that concepts in organic chemistry do not apply to inorganic compounds.
Since organic compounds are different from inorganic compounds, students often think that concepts in inorganic chemistry do not apply to organic chemistry.
Clarification: Organic functional groups are often found in inorganic compounds and thus, they share the same chemical properties.
As an activity to address this misconception, you can have students conduct an investigative lab on the properties of alcohols. In this lab, students can explore the solubility of alcohols in polar vs non-polar solvents. Students should conclude that both water (inorganic compound) and alcohols (organic compound) contain a polar hydroxyl group (–OH), which is an organic functional group. The hydroxyl group gives both molecules a polar property and thus, both are soluble in polar solvents.
Clarification: Organic functional groups are often found in inorganic compounds and thus, they share the same chemical properties.
As an activity to address this misconception, you can have students conduct an investigative lab on the properties of alcohols. In this lab, students can explore the solubility of alcohols in polar vs non-polar solvents. Students should conclude that both water (inorganic compound) and alcohols (organic compound) contain a polar hydroxyl group (–OH), which is an organic functional group. The hydroxyl group gives both molecules a polar property and thus, both are soluble in polar solvents.
5. Students often think that the term 'condense' and 'reduce' means something is getting smaller.
Condensation reactions: something takes up less space. Reduction reactions: something is made smaller or is reduce.
Clarification:
Condensation reactions are reactions in which two compounds are combined and water is released.
Reduction reactions involve adding a hydrogen to a double bond.
Activity: Show video animations of condensation and reduction reactions or use molecular model kits to demonstrate what exactly happens to the atoms during a condensation and reduction reaction.
Condensation reactions are reactions in which two compounds are combined and water is released.
Reduction reactions involve adding a hydrogen to a double bond.
Activity: Show video animations of condensation and reduction reactions or use molecular model kits to demonstrate what exactly happens to the atoms during a condensation and reduction reaction.
6. Students may think alcohol is a drink.
Alcohols in chemistry are functional groups defined by the presence of a hydroxyl group (-OH). Alcoholic beverages contain ethanol, which is one type of alcohol, specifically consists of 2 carbon atoms and a hydroxyl group. As an activity, you can have students compare different types of alcohols and identify the common functional group (-OH) present in all. This misconception can also be used as a teachable moment where you can can also lead into a discussion on the toxicity of ethanol and how it affects the mind, body and society.
7. Students often think that all polymers are synthetic.
All of the important biological macromolecules in living organisms are polymers; this includes proteins, DNA, RNA, and carbohydrates. Wool, hair, and fingernails are made mostly of polymers too.
8. Students often think that a polymer is a long chain of identical units.
This is partially true. There are still some polymers that are made up of alternating units of different molecules.