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Differentiate: tan(2x) cos(x)

Explain the product rule : d/dx ( f(x) . g(x) ) = f'(x).g(x) = g'(x) . f (x) 2. Briefly run through trigonometric derivatives .* cos (x) differentiates to: -sin(x)* tan (x) differentiates to: sec^2 (x) 3. Br...
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Answered by Shreyasi D. • Maths tutor
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Bethan prepared some ethoxyethane (line 6) by reacting ethanol with concentrated sulfuric acid. She used 69g of ethanol (Mr=46) and obtained a 45% yield of ethoxyethane (Mr=74). Calculate the mass of ethoxyethane obtained.

Equation from line 6 is: 2 (ethanol) -------> 1 (ethoxyethane) 2. The ratio of reaction is 2:1. This is the ratio of moles not mass , i.e., 2 moles of ethanol give 1 mole of ethoxyethane. 3. We need to kn...
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Give the name of the monomer used to make poly(chloroethene). And describe how monomer molecules form polymer molecules.

Briefly explain the etymology of hydrocarbon names and how polymers are named. The answer is therfore, chloroethene. 2. Draw a structure for chloroethene and show in diagram how chloroethene polymerises. 3. ...
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Explain the trends in electronegativity in the periodic table

As you go across the period from left to right (excluding noble gases), electronegativity increases. This is because the nuclear charge increases (Atomic Number/number of protons) and atomic radius decreases...
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Answered by Anika P. • Chemistry tutor
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'The League of Nations failed principally because the USA was not a member'. To what extent do you agree with this statement?

10 mark answer" The League of Nations failed for several reasons: the USA was not a member; its most powerful members, Britain and France, were motivated by self-interest; and any decision taken had to ...
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Answered by Catherine R. • History tutor
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