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Explain in terms of particles and collisions how concentration, temperature and addition of a catalyst affect the rate of a reaction.

Concentration: the higher the concentration, the more particles in the same volume. The increase in particle numbers causes an increase in particle collisions, so the rate of reaction increases.Temperature: ...
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Answered by Emily W. • Chemistry tutor
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Calculate the pH of a 0.0131 mol dm^-3 solution of calcium hydroxide at 10 degrees centigrade.

Multiply by 2 because calcium hydroxide = Ca(OH)2 so 2 x [OH-] per molecule.[OH-] = 0.0131 x 2 = 0.0262 Insert [OH-] value into the equilibrium equation along with the value of Kw at 10 degrees centigrade 2....
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Answered by Emily W. • Chemistry tutor
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Explain why adding small amounts of acid or base hardly changes the pH of an acidic buffer solution.

An acidic buffer solution is made up of a weak acid (e.g. ethanoic acid) and a salt containing its conjugate base (e.g. sodium ethanoate). It resists pH change via two mechanisms: The fact that the acid is w...
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Name and explain the process in which crude oil is separated into fractions. (5 marks)

The process is fractional distillation : the separation of a mixture using heat. The crude oil is heated and the mixture will evaporate . The mixture will then rise up the column and cool as it rises as the ...
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Answered by Emily P. • Chemistry tutor
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Describe the bonding present in a piece of sodium metal.

A lattice of positive sodium ions with a sea of delocalised electrons distributed around them. The metallic bond consists of the electrostatic force of attracion between the positively charged sodium atoms a...
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Answered by Mark C. • Chemistry tutor
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