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What are the 2 methods used to manufacture ethanol? What are the advantages and disadvantages of both?

The hydration of ethene: Ethene and steam are passed over a catalyst - concentrated phosphoric acid (H 3 PO 4 ) - at 300 O C and 60-70 atmospheres. This process is fast, continuous and gives a pure product b...
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Answered by James P. • Chemistry tutor
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How is the the small intestine adapted for absorption?

The Ileum is long (up to 7m!) and has a very high surface area due to the presence of many villi and microvilli . A single villus is made up of many cells, each with lots of microvilli, and have many blood v...
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Answered by James P. • Biology tutor
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A stationary point of inflection implies a second derivative of 0, does this work the other way around?

No, and we may take a counterexample to see why. If y=x^5+5/3x^4, dy/dx=5x^4+20/3x^3, d2y/dx2=20x^3+20x*2=20x^2(x+1). Setting this to 0 will give us the candidates for a POI, but not all these numbers will b...
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Answered by Toby R. • Maths tutor
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Why is adolescence a critical period in human development?

The period between childhood and adulthood is a time of great transition and turbulence with regards to changing bodies, close relationships, and expectations. It is one of the most rapid phases of developme...
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Answered by Chloe K. • Psychology tutor
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Tetrodotoxin (TTX) is a chemical found in pufferfish which binds to voltage-gated sodium channels causing inactivation via a conformational change. Poisoning can result in paralysis leading to death. How might this occur? (4 marks)

This question asks about nerve action potential generation. There are a couple of clues - these include 'voltage-gated sodium channels' and 'paralysis' which suggests the idea of failure of impulse transmiss...
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Answered by Rafee A. • Biology tutor
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