Alkenes

Question 1

Why are alkenes fairly reactive

Answer 1

Double bonds have a high electron density

Question 2

Cycloalkenes

Answer 2

Have two fewer hydrogens than the straight chain version of the same molecule. Eg C5H8 instead of C5H10

Question 3

Sigma bonds

Answer 3

When two orbitals overlap and they align horizontally to give a single covalent bond.

Question 4

Pi bonds

Answer 4

Parallel overlap of two p orbitals

Question 5

Why does pi bonds have lower bond enthalpy

Answer 5

They are weaker and electron density is spread out above and below the nucleus. So electrostatic attraction is weaker

Question 6

Why are alkanes not as reactive as alkenes

Answer 6

Alkanes are non polar

Question 7

What are alkenes good for

Answer 7

Polymers and petrochemicals

Question 8

electrophile

Answer 8

electron pair acceptor

Question 9

Why do it different to data book values and how to improve

Answer 9

Heat losses
Incomplete combustion
Data book uses standard values
Evaporation of water from beaker
Copper can instead of beaker
Standard conditions
3DP mass balance
Heat for longer to reduce % uncertainty in mass