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Chemistry

A Level

a) How can an element be classified as a transition metal, considering only electronic arrangement? (1 mark) b) In terms of electrons, why is aqueous copper(II) sulphate solution red? (3 marks) c) EDTA is a bidentate ligand. What is a bidentate ligand?(2)

a) Partially filled/incomplete d shell.
b) Light is absorbed by an electron, exciting it and is promoted to a higher energy d orbital. The colour seen is the complimentary colour of that absorbed (in...

Answered by James O. • Chemistry tutor

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25cm^3 of 0.1M NaOH is reacted with 0.01M HCl until the equivalence point is reached. What volume of HCl was required to be added?

0.025 dm^3 x 0.1 mol dm^-3 = 0.0025 molsince mols must be equal:mols of HCl = 0.0025/0.01 =250cm^3To get to the answer I would first check the student was first able to identify the key words and numbers ...

Answered by Georgina W. • Chemistry tutor

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What is covalent character, how does it arise. List a compound it does affect and explain the resulting properties covalent character affects.

Covalent character occurs in ionic bonds when the postive (usually metal) ion is highly charge dense and can polarise the counter ion causing electrons to be shared between the two ions rather than electr...

Answered by Jake V. • Chemistry tutor

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How do you decide what the sign of the enthalpy change should be?

You have to think about whether or not energy is being released by the system into the surroundings (exothermic), or whether the system is taking energy up from the surroundings (endothermic).You have to ...

Answered by Ben W. • Chemistry tutor

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