Alkenes & Alkynes

Introduction

https://www.youtube.com/watch?v=CEH3O6l1pbw

A video about alkenes & alkynes, their structures, and how to remember which is which by simply knowing the alphabet.

You will find an explanation of what hydrogenation, halogenation, polymerization, and triglycerides are, all while helping you to figure out the meaning of different names for fats.

Task

Before watching the video, read through all the questions in the task.  

After watching the video about alkenes and alkynes, try to answer as many questions as you can from the task to test your knowledge.

 Check your answers!

Process

  1. What are alkanes?
  2. What are alkenes?
  3. What are alkynes?
  4. What is isomerism?
  5. Which are more unstable – pi bonds or sigma bonds?
  6. How many valence electrons does the carbon atom have?
  7. Alkanes are much more stable than alkenes because of the presence of the C=C double bond – is this statement true?
  8. What fats are called saturated?
  9. What do food chemists use to saturate the unsaturated fats?
  10. Is the compound shown in the picture a cis– or a trans– isomer?

  11. What is the name for the compound shown in the picture?

             a) Propane

             b) Propyne

             c) Propene

 

 

 

Evaluation

The correct answers:

  1. Alkanes are saturated hydrocarbons, they have only single bonds
  2. Alkenes are unsaturated hydrocarbons that contain at least one double bond
  3. Alkynes unsaturated hydrocarbons containing at least one triple bond
  4. It is when certain compounds have similar molecular but not structural formulas
  5. Sigma bonds
  6. 4
  7. This statement is incorrect. Alkenes are more reactive than alkanes due to the double bond
  8. Fats that contain no double bonds in fatty acid chains
  9. Hydrogenation
  10. Cis– isomer, because the matching groups are on the same side of the carbon chain
  11. d is the correct answer, the compound is an alkene because of the double bond

Conclusion

Correct answers

Level of knowladge

1 - 3

Very poor, read through again and try once more!

4 - 5

Below average, find out your mistakes and try again!

6 - 7

Good/average, but you can do better!

7 - 9

Very good/ above average, you have done good job!

10 - 11

Excellent! Thank you!

 

Hydrocarbons are the basis of organic chemistry and it is important to perfect the fundamentals right in the beginning. The knowledge about alkenes and alkynes you gained from this webquest, will help you to understand organic chemistry better.