Prelab assignment
**Ethylenediamine should be abbreviated "en". **
**Tris (etheylenediamine) nickel (H) chloride should be abbreviated "Ni (en) 3Cl2". **
1. Describe a Lewis acid and Lewis base.
A Lewis acid is usually a Cat ion that accepts electron from an unshared one. While Lewis base is a nucleophilic and more often an Anion that donates a lone-pair of electrons (Leach, 1999).
2. Using the reaction to be performed in this lab, determine the limiting reactant if 1.3 g NiCl2.6H2O and 11 ml 1.4 M ethylenediamine are reacted.
Since it has less ethylenediamine required to react all of the NiCl2.6H20, then ethylenediamine is the limiting reactant.
Calculation:
NiCl2.6H20+ 3NH2CH2CH2NH2 -> [Ni (NH2CH2CH2NH2)3] Cl2+6H2O
(1.3 g NiCl2.6H20) x [(1 mole NiCl2.6H20)/ (237.69 g)] x [(3 moles NH2CH2CH2NH2 )
/ (1 mole NiCl2.6H20)] = 0.0213 moles NH2CH2CH2NH2
(0.011L NH2CH2CH2NH2) x [(1.4 moles NH2CH2CH2NH2)/ (1 L)]
= 0.0154 moles NH2CH2CH2NH2
3. Calculate the theoretical yield (in grams) of tris (etheylenediamine) nickel (II) chloride from question #2.
Base on the first experiment, the sample has1.5649g of [Ni (NH2CH2CH2NH2)3] Cl2 that were collected, given the 1.2 g NiCl2.6H20. For the 1.3g of NiCl2.6H20, the sample has 1.6949 g of [Ni (NH2CH2CH2NH2)3] Cl2 were produced. Therefore, the percent yield is 92%.
NiCl2.6H20+ 3NH2CH2CH2NH2 -> [Ni (NH2CH2CH2NH2)3] Cl2+6H2O
Calculation:
(1.3 g NiCl2.6H20) x [(1 mole NiCl2.6H20)/(237.69 g)] x [(1 mole[ Ni(NH2CH2CH2NH2)3]Cl2/(1 mole NiCl2.6H20)] x [(309.8936 g
[Ni (NH2CH2CH2NH2)3]Cl2)/ (1 mole [Ni (NH2CH2CH2NH2)3]Cl2 )]
= 1.6949 g [Ni (NH2CH2CH2NH2)3] Cl2
% Yield = [(1.5649g)/ 1.6949 g] x 100 % = 92%
4. Calculate the % yield of precipitate from question #2 if 1.11 g were recovered.
Base on the data above, from 1.11 g were obtained, we’ve come up with a percent yield of 65.49%.
% Yield = [(1.11 g)/ 1.6949 g] x 100 % = 65.49%
Work Cited
Leach, M. (1999). Meta-synthesis:Webbook. Retrieved from http://www.meta-synthesis.com/webbook/12_lab/lab.html
