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Chemistry

A Level

A chemist synthesised two solutions A and B, they know one solution is an aldehyde and the other a ketone. Suggest how the chemist could identify which is which and describe any observations they would make

Tollens reagent could be used to identify the the solutions A and B, as the aldehyde solution will oxidise to a carboxylic acid and a ‘silver mirror’ will be observed. Ketones cannot be oxidised further a...

Answered by Hugo J. • Chemistry tutor

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Why is the Mg2+ ion smaller in radius than the Na+ ion?

The magnesium ion is in group two of the periodic table, whereas sodium is in group one. This means that magnesium has one more proton than the sodium ion, so it has a more positive core. Both ions have t...

Answered by Olivia D. • Chemistry tutor

9378 Views

The enthalpy of combustion of ethanol is −1371 kJ mol−1 . The density of ethanol is 0.789 g cm−3 . Calculate the heat energy released in kJ when 1 dm3 of ethanol is burned.

1 dm3 of ethanol is equal to 1000 cm3, so the mass of ethanol used is =density x volume = 0.789 g cm-3 x 1000 cm3 = 789gMolar mass of ethanol = (2x12)+(6x1) +(1x16)= 46 g mol-1Moles of ethanol = mass/mola...

Answered by Sophie L. • Chemistry tutor

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Why are complex ions containing transition elements coloured?

Firstly a transition element is an element which forms one or more stable ions with incompletely filled d orbitals.Ligands are charged or neutral, ions or molecules, which form coordination bonds with a c...

Answered by Josephine R. • Chemistry tutor

8833 Views

How can you tell if a reaction is feasible and what factors contribute towards this?

A reaction is said to be feasible or spontaneous when the Gibbs Free Energy (Delta G) of the reaction is <0. Conversely, when the Gibbs Free Energy (Delta G) of the reaction is >0,...

Answered by Jamie R. • Chemistry tutor

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