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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

2541 Views

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

26753 Views

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

1964 Views

Calculate the percentage composition by mass of Lithium Sulfate, Li2SO4.

(Taken from GCSE WJEC Additional Science Book- First Published in 2012) and I have adapted the answer given.Relative atomic masses: Li = 7 ; S= 32 ; O=161) Calculate molecular mass of lithium sulfate (Li2...

Answered by Elinor L. • Chemistry tutor

16552 Views

What is the electronic configuration of Calcium?

Calcium has 20 electrons.
The first ring can only contain up to 2 electrons.After that rings can only contain up to 8 electrons.
Therefore the electronic config...

Answered by Jonny M. • Chemistry tutor

13255 Views