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Give the molecular formula of benzene. Give the Kekule structure of benzene and then explain why this structure is not correct. Give the accepted structure for benzene (5 marks).

Molecular formula: C 6 H 6 The Kekule structure (draw on whiteboard in session) - has the hexagonal shape of the ring, with a carbon=carbon double bond on every other carbon-carbon link. This has been proven...
BS
Answered by Ben S. • Chemistry tutor
3239 Views

Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria.

Sugar is a solute, so honey contains a high concentration of solutes. This increases the solute potential, and decreases the water potential of honey, which is therefore lower than the water potential in bac...
NK
Answered by Nighat K. • Biology tutor
4019 Views

Differentiate, with respect to x, e^3x + ln 2x,

e^3x differentiates to 3e^3x as you multiply the function e^3x by the derivative of the inside function 3x. 3x differentiates to 3, so the answer is 3 multiplied by e^3x. The derivative of a natural log func...
PA
Answered by Pelumi A. • Maths tutor
13937 Views

What do I need to include in order to answer a 'how valuable' source question effectively?

At A level, there are 3 key elements of these source questions that must be addressed in any answer. These are: 1) content, 2) provenance and 3) tone. Discussing each one in turn: 1) The content of the sourc...
SF
Answered by Samuel F. • History tutor
11455 Views

Give three features of an efficient exchange surface. Provide an example for each feature.

An efficient exchange surface should have a high surface area as this increases the rate at which diffusion can occur across it. For instance, roots have many root hair cells. These root hair cells have thin...
EH
Answered by Elliot H. • Biology tutor
16730 Views