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Chemistry

A Level

Describe how a buffer solution based on hydrochloric acid can act as a buffer. (5)

HCl ⇌ H++ Cl- (1)Added alkali: H⁺ reacts with added alkali/OH^-(1) Equilibrium shifts right forming Cl^- or H⁺(1) Added acid: Cl<...

Answered by Daisy R. • Chemistry tutor

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Explain what the rate-determining step in a reaction is with reference to activation energy.

The rate determining step is the slowest step in a multi-step reaction, and it is the step in the reaction with the highest activation energy. It is the step in the reaction which decides the overall rate...

Answered by Sammy A. • Chemistry tutor

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When propanal is reacted with potassium cyanide under weakly acidic conditions the resulting mixture does not rotate plane polarised light. Explain this observation.

A common mistake is to answer this question with the explanation that the light is not rotated because no optical isomers are present. However, this is incorrect. The only other time where plane polarised...

Answered by Sally D. • Chemistry tutor

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Periodicity shows a fairly smooth increasing trend across a period for ionisation energy. However, between groups 2 & 3 and groups 5 & 6, the trend doesn't appear to be followed. Using your knowledge of chemistry, explain why the trend isn't followed here

For elements in group 2, their valence electrons consist of "ns²" where n is the principle quantum number/shell number. However, for elements in group 3, their valence electrons consi...

Answered by George W. • Chemistry tutor

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Draw the full structual diagram of ethyl-ethanoate, labeling relevent bond angles and explain why the molecule has this structure.

(unable to draw diagram and upload in this format) ethyl ethanoate has the semi structural formula of CH3COOCH2CH3. According to electron repulsion theory the bond angle around the second carbon atom woul...

Answered by • Chemistry tutor

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