BTEC Applied Science - Unit 5 Chemistry - Free radical substitution in Alkanes

[@nooh6842]

Thank you again, understanding has massively increased with this video and thanks for your help Sir. The general formula for alkanes is CnH2n+2 has a carbon-carbon C-C bond and has saturated hydrocarbons.

[@navjutla]

Blessing my feed once again, thank you so much!

[@fayehorry1393]

This was the exact video I needed!

[@humaymahyaser74]

For q3 for 14:09. Can I show the equation and give explanation to give me 6 marks . Or would I have to show just equation.

[@BrysonChemistry]

If you name the three stages and give all 4 equations then it’s full marks. No explanation needed

[@mrkebab9051]

Free radical addition showed up as a 6 marker in the unit 5 paper today instead of free radical substitution

[@BrysonChemistry]

I’ve not seen the paper yet!

[@georgia2455]

why do one of the carbons become a free radical on the first step pf propagation?

[@BrysonChemistry]

The Cl free radical removes a H leaving the C a free radical

[@EmmaBoylan-y3n]

On the second step of the propagation, why did the CH2CH3 carbon free radical react with Br2? I thought the Br2 from the beginning was broken by UV light to create two Br free radicals and then one of them was used to bond with ethane to form HBr and the CH2CH3 free radical. So where did the Br2 come from in the second propagation step? I'm sorry for the long question, I'm just trying to get a proper understanding. it seems like you're pulling molecules that you've already reacted with other things and reusing them, like Br2 and the CH2CH3 from the termination step, is that the case? Or have a misunderstood.

[@BrysonChemistry]

Thanks for the question. You have to remember that this is a chain reaction so there are many of each molecule present. This reaction is driven by free radicals. Initiation is what starts the reaction and free radicals are formed. A propagation step will always have a free radical as a reactant and a free radical as a product…google definition of ‘propagation’ A termination step will terminate the reaction, so two free radicals come together to form a non free radical.

[@fanoor2427]

Is there a textbook for BTEC Applied Science?

[@BrysonChemistry]

Yes and a revision guide. Try Amazon or Ebay

[@oyinolaa]

THANK YOU SO SO MUCH for this video! I honestly had no clue about free radical substitution, literally learnt more from you in 14 minutes than a hour and a half with my chem teacher 😄

[@BrysonChemistry]

Pleased you found it useful...good luck in the exam

[@iRipper_xD]

just yestrday we had the same mock exam you showed in vid, wooww bro i love you

[@BrysonChemistry]

🤣🤣 that’s fortunate

[@nooh6842]

There are 3 steps to this: Initiation, Propagation and Termination.

[@BrysonChemistry]

Correct…but the second step has two equations to it. Does that make sense?

[@nooh6842]

@@BrysonChemistry Yes Thankyou I understand it now, could you do a video on naming hydrocarbons?

[@sumairamahmood838]

Thankyou

[@abalk1]

Thank you very much for the video sir. I have checked the mark scheme for the 6 marker question, I just wanted to ask if I would still get full marks for just putting in the equations or do I still have to explain fully

[@BrysonChemistry]

I would advise you to make sure you name each step and write a sentence to support each step

[@abalk1]

@@BrysonChemistry Thank you so much my friend, much appreciated. Keep up the good work :)

[@luv1508]

Does it matter where the (free radical electrons •) is?

[@BrysonChemistry]

It should be on the C where the substitution is happening

[@humaymahyaser74]

Thanks for the video

[@Hotstanna]

Can this apply to CTEC science

[@BrysonChemistry]

What is CTEC?

[@danielogwezi358]

BTEC yes

[@BrysonChemistry]

@@danielogwezi358 yes, this series of videos is for BTEC Applied Science

[@Hotstanna]

@@BrysonChemistry it’s OCR exam board of BTEC. I think it’s the same thing but different exam board

[@BrysonChemistry]

@ ah ok…well chemistry is chemistry so if this topic in on there then yes it’s relevant