# A level Chemistry help.

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#1
I don't get this explanation (wait for screenshots).
Quesrion 1b
Last edited by Mad Man; 3 weeks ago
0
3 weeks ago
#2
I don't get this explanation (wait for screenshots).
Quesrion 1a
There is no explanation for 1a, its a quotient relationship between product and reactant concentrations
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#3
(Original post by charco)
There is no explanation for 1a, its a quotient relationship between product and reactant concentrations
1b sorry.
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3 weeks ago
#4
1b sorry.
Have you ever done an ICE table?

This is a rather easy example of one.
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#5
(Original post by Pigster)
Have you ever done an ICE table?

This is a rather easy example of one.
No I haven't, can you please explain it?
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#6
I want to know why the molar value for h20 is the same as the c2h5
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3 weeks ago
#7
I want to know why the molar value for h20 is the same as the c2h5
Because they are in the same ratio in the equation.
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#8
(Original post by CGD1997)
Because they are in the same ratio in the equation.
but so is the ethanol
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3 weeks ago
#9
at equilibrium, you know that 1 mole of each will decompose (whichever direction the reaction is going). so for the backwards reaction, 1 mole of C2H5OH will produce 1 mole of C2H4 and H20.

to find how much 1 mole is, you subtract how many moles of products minus reactants. so, 5-1.85, as you started with 5, and the equation states that 1 mole is used to produce 1 mole of the C2H4 so it is used up from the 5. as the H2O and the C2H4 are the same molar ratios, the same amount of each are produced. therefore

C2H4 = 1.85 mol
H20= 1.85 mol
C2H5OH = 3.15 moles left.

remember, you don’t subtract the 1.85 twice from the 5, as the equation states that only one mole is used of the C2H5OH to make two moles of product. hope this helps if you haven’t figured it out already 0
#10
(Original post by bzkldn)
at equilibrium, you know that 1 mole of each will decompose (whichever direction the reaction is going). so for the backwards reaction, 1 mole of C2H5OH will produce 1 mole of C2H4 and H20.

to find how much 1 mole is, you subtract how many moles of products minus reactants. so, 5-1.85, as you started with 5, and the equation states that 1 mole is used to produce 1 mole of the C2H4 so it is used up from the 5. as the H2O and the C2H4 are the same molar ratios, the same amount of each are produced. therefore

C2H4 = 1.85 mol
H20= 1.85 mol
C2H5OH = 3.15 moles left.

remember, you don’t subtract the 1.85 twice from the 5, as the equation states that only one mole is used of the C2H5OH to make two moles of product. hope this helps if you haven’t figured it out already But if they are in the same ratio, surely c2h5oh will be 1.85?
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3 weeks ago
#11
n
But if they are in the same ratio, surely c2h5oh will be 1.85?
no, because the original amount of moles put IN is 5. the reaction is the backwards reaction so “1 mole” (in terms of the reaction ratio) is USED. 1.85 is USED, not made, no amount of c2h5oh is made in this reaction. therefore as 1 mole is used you subtract one mole (1.85) from the original amount to produce 3.15
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