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What does Le Chatelier's principle say happens to an equilibrium when temperature is changed or a catalyst is added?

The temperature moves the equilibrium differently depending on if the forwards reaction is exothermic or endothermic. If its endothermic the equilibrium moves to the right giving more products. The addition ...
Answered by • Chemistry tutor
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State and explain the trend in boiling points of chlorine, bromine, and iodine

Boiling point increases down the group, because of increasing strength of van der Waals (intermolecular) forces. More energy is required to break van der Waals (intermolecular) forces.Follow up questions cou...
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What is the coefficient of x^4 in the expansion of (x+3)^7

Start by expanding (a+b) 7 , using Pascal's Triangle or the binomial coefficient function to work out the coefficients:a 7 + 7a 6 b + 21a 5 b 2 + 35a 4 b 3 + 35a 3 b 4 + 21a 2 b 5 + 7ab 6 + b 7 , where a=x a...
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Answered by Josef W. • Maths tutor
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Integrate 1/(1 - 3*x) with respect to x

First substitute: u = 1 - 3xNext calculate: du/dx = -3 .... therefore dx = (-1/3) * duNow re-arrange the expression: Integrate 1/u * ( -1/3)*duNext recall the integral of 1/x is the natural logarithm, and re...
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Answered by Neil M. • Maths tutor
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Outline the advantages and disadvantages of one named hard engineering river flood management strategy. (6 marks)

Named flood management strategy: DamsDams are the classic hard engineering solution to flooding problems. A dam is a giant wall built across a river’s channel to impede its flow. Water builds up behind the d...
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