Obtain the valence shell configuration of Al and S from their positions in the periodic table.
1 answer:
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Answer:
a) 1,74 molal
b) 37,2 %
c) 0,03
Explanation:
We are going to define sucrose as solute, water as solvent and the mix of both, the solution.
Let´s start with the data:
We can assume as a calculus base, 1 liter of solution. So, in 1 liter of solution we have 1,22 moles of solute:
Knowing that the molality (m) is defined as mol of solute/kgs solvent, we have to calculate the mass of solvent on the solution. Remember our calculus base (1 lts of solution). In 1 lts of solution we have 1120 grams of solution.
With the molecular weight of solute (<em>Sum of: for carbon = 12*12=144; for hydrogen = 1*22=22 and for oxygen = 16*11=176. Final result = 342 grs per mol</em>), we can obtain the mass of solute:
Now, the mass of solvent is: mass solvent = mass of solution - mass of solute. So, we have: 1120 - 417,24 = 702,76 grs of solvent = 0,70276 Kgs of solvent
For b) question we have that the mass percent of solute is hte ratio between the mass of solute and the mass of solution. So,
For c) question we have that the mole fraction of solute is the ratio between moles of solute and moles of solution. Let's calculate the moles of solution as follows: <em>Moles solution = moles solute + moles solvent.</em> First we have that the moles of solvent are (remember that the molecular weight of water for this calculus is 18 grs per mol):
So, we have the moles of solution: 1,22 moles of solute + 39,04 moles of solvent = 40,26 moles of solution
Finally, we have:
Answer:
See explanation and images attached
Explanation:
a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.
b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.
