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Chemistry

A Level

Explain why the 2nd Electron aiffinity of Chlorine is Endothermic whilst the first electron affinity is exothermic

With the first electron affinity, the chlorine atom is one electron from a full octet ( and is a neutral species). When you add an electron to the chlorine, the negatively charged electron is electrostati...

Answered by Hayden C. • Chemistry tutor

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Suggest why Phenol is more reactive than Benzene in Electrophillic Substitution

With phenol, the oxygen atom is directly attached to the delocolised pi system in phenol, as a result the lone pair on this oxygen is incorporated into this delocolised pi system in phenol, increasing it'...

Answered by Hayden C. • Chemistry tutor

2195 Views

Why does reacting a bromoalkane with ammonia result in a quaternary ammonium salt and not an amine?

To explain this question let us use an example of reacting Bromoethane (CH3CH2Br) with ammonia (NH3). As bromine is more electronegative than carbon (electronegativity being the ability of an element to a...

Answered by Henry D. • Chemistry tutor

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You have 3.51g of hydrated zinc sulphate. You heat up the zinc sulphate until all the water has evaporated from it. The weight after heating is 1.97g. Find how many H2O molecules per zinc sulphate molecule there are in the hydrated form of it.

Write down the equation: ZnSO4xH2O --> ZnSO4 + xH2O 2. Calculate the masses: 3.51g --> 1.97g + 1.54g 3. Calculate the number of moles, using the molar mass of water and zinc sulphate: 1.97g = ...

Answered by Olivier S. • Chemistry tutor

21497 Views

What is entropy and how is it used in chemistry?

Entropy (S) is a measure of disorder in a system. Any process, in this case a chemical reaction, is said to entropically favoured if the overall disorder in the system increases. This is usually when ther...

Answered by Kashf S. • Chemistry tutor

2605 Views