Heat of combustion is a chemical property that can be measured.
The balanced reaction is
3Na3PO4 + 2CuSO4 ------> 3Na2SO4 + Cu3(PO4)2
To balance this reaction of double displacement, we see first that this reaction maintain the valence numbers of every atom.
Then, to have the same value of Na in the two sides of the reaction we multiply for the number of the other side. So,
(Na3PO4)x 2
(Na2SO4)x3
As we can see either, we need to balance PO4 cause there are two molecules of this in the reactant side, so we have two molecules of PO4 in the product either.
Then we get
3Na3PO4 + 2CuSO4 ------> 3Na2SO4 + Cu3(PO4)2
To probe that balance was correct, you can verify that the charges are exactly the opposite.
The valence electrons is last outer shell of an atom. So it is the last number of the electron configuration on the periodic table.
Answer:
Yes
Explanation:
Yes, you can test this by comparing grades you received when you studied and when you did not study
Answer:
The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.
Explanation:
The Molar Fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution, which are calculated by adding the moles of solute (s) and solvent.
It is calculated by dividing the number of moles of one of the components by the total number of moles of the solution.
The sum of all the molar fractions of the substances present in a solution is equal to 1.
So, the expression to calculate the mole fraction is:

Being the molar mass of the compounds:
- Ethanol 46
- Water 18

the number of moles that represent the mass quantities is calculated as:
- Moles of ethanol: 300 grams*
= 6.52 moles
- Moles of water: 500 grams*
= 27.78 moles
So the total moles in solution are 6.52 moles + 27.78 moles = 34.3 moles
The mole fraction of ethanol in the solution is calculated as:


The mole fraction of water in the solution is calculated as:


Then:


<u><em>The mole fraction of ethanol and water in the solution are 0.19 and 0.81 respectively.</em></u>
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