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Chemistry

A Level

What is the definition of Avogadro's constant and when should I use it?

Avogadro's constant is defined as the number of atoms/molecules in one mole of a substance. It's value is approximately 6.023 x 10^23.

It is often used in conjunction with the equa...

Answered by Ben K. • Chemistry tutor

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Explain what is meant by the term 'rate of reaction'?

The change in concentration of reactants or products, per unit of time.

Answered by Laura M. • Chemistry tutor

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What is solvent leveling? How can we distinguish between two strongly acidic solutions? (This is a challenging question and is included for interest only)

Solvent levelling refers to the effect of the solvent on the properties of acids and bases. The apparent acidity of a solution is limited, or levelled, by the basicity of the solvent it is in. A very stro...

Answered by James C. • Chemistry tutor

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Briefly discuss Le Chatelier's Principle. Ammonia is made in the Haber Process (3H2(g) + N2(g)<-> 2NH3(g)). Using Le Chetelier's Principal, what happens to the equilibrium yield of ammonia when...: A) Temp increases, B) Press increases C) Catalyst changes

Le Chetelier's Principal gives us a guide to work out what will happen when we change the conditons of a reaction in dynamic equilibrium. It states that if the dynamic equilibiurm is disturbed, the equili...

Answered by James C. • Chemistry tutor

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Write down the equation for the Gibbs Free Energy change of a reaction. Hence explain why, for a spontaneous endothermic reaction, there must be an increase in the total entropy.

Gibbs Free Energy change: (delta)G = (delta)H - T(delta)S For a spontaneous chemical reaction, (delta)G must be negative. An endothermic reaction has a positive (delta)H value therefore, in order for the ...

Answered by James C. • Chemistry tutor

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