These are three organic chemistry questions

Question

These are three organic chemistry questions

regarding stability. Can you please help explain why a primary carbocation is less stable than a tertiary, why BH3 THF is a better reagent than NaBH4, and how the products of hydroboration/oxidation reactions differ in stability by whether it is an alkene or alkyne?

The stability of radicals and carbocations follow the same trend . With this rational in mind , explain
Why a primary carbocation formed during the electrophilic addition of H – Br to an alkene is less stable
than the corresponding tertiary carbocation
5 ) Explain why BH 3 – THE is an excellent reagent for the hydroboration of alkenes , while
ile NaBHA does not
react in a similar fashion
In the hydroboration / oxidation of alkenes , the final product resus in the formation of the an
Markovnikov alcohol . However , when this same reaction is conducted with allynes , the product that
is formed is the ketone or aldehyde . Explain this observation in terms of energetics and stability
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