Answer:
Reagent A: PBr₃
Reagent B: Mg in Et₂O.
Explanation:
Hello,
In this case, your facing a problem in which a carboxylic acid is produced starting by an alcohol. More specifically, cyclopentanol must react with phosphorous tribromide in order to yield bromocyclopentane which is more likely to produce a carboxylic acid, therefore, reagent A is PBr₃.
On the other hand, by means of the production of the specified product, bromocyclopentane must react with carbon dioxide and magnesium in diethyl ether in acidic media to promote the production of the cyclopentanoic acid via the grignard reaction (substitution of the bromine by the carboxyle group), therefore, reagent B is Mg in Et₂O.
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Xe +f2 →Xef2
ΔXe = ΣB.P reactants - Σ B.d products
-108k.s/ mol = B. D f₂ - 2 B.D xe-f
-108 k.s/mol =155 k.s/mol - 2B.Dxe-f
263kJ/mol/2 = B. D xe-f
B.D xef = 131.5 kJ/mol
132 kJ/mol
One possible answer could be that a chemical reaction has occurred.
Zn+2HCl ----> 2ZnCl2 + H2
For 2.50 g of Zn
Mass per mol = 2.50/molar mass of Zn = 2.50/65.38 = 0.0382 g/mol
There are two moles of ZnCl2 and total mass = 2*0.0382*molar mass of ZnCl2 = 2*0.0382*136.286 = 10.42 g
For 2 g of HCl
Mass per mol = 2/2*molar mass of HCl = 2/ (2*36.46) = 0.0274 g/mol
For the two moles of ZnCl2, mass produced = 2*0.0274*136.286 = 7.48 g
It can be noted that 2 g of HCl produced less amount of ZnCl and thus it is the limiting reagent.
Answer:
Explanation:
Heat required to convert ice to ice at 0⁰C
= mass x specific heat x rise in temperature
= 18 x 2.09 x 20
= 752.4 J .
heat required to convert ice at 0⁰C to water at 0⁰C
mass x latent heat of fusion
= 18 x 336
= 6048 J
Heat required to increase the temperature of water to 100⁰C
= 18 x 4.2 x 100
= 7560 J
Total heat required
7560 + 6048 + 752.4
= 14360.4 J