NMR Studies
Preparation of a mixture of methyl, ethyl and 2-propyl salicylates and determination of % ratio by GC and HNMR spectroscopy
INTRODUCTION:
Figure 1: Formation of ester from carboxylic acid.
MECHANISM:
When the carboxylic acid is treated along with the acid catalyst and alcohol[R-OH], It gives rise to the formation of ester along with water. Furthermore alcohol is used in an excess amount in the reaction, because this reaction is probably in equilibrium. Whereas alcohol is employed as a solvent, so it is used quiet larger in the reaction mechanism. Various other acids can also be used as the solvent for the formation of the ester such as sulphuric acid[H2SO4] and tosic acid[TSOH]. In this experiment Methyl salicylates are prepared along with ethyl and 2-propyl salicylates in which the reaction proceeds with salicylic acid as the starting material along with the other reactants such as methanol, ethanol and 2-propanol. More specifically, sulfuric acid is employed as the suitable acid catalyst.
FIGURE 2: Formation of methyl salicylate from salicylic acid.
2. CALCULATION: PERCENTAGE YIELD OF THE PRODUCT: In order to calculate the percentage yield of the product , we need to calculate the theoretical yield. Percentage yield = actual yield/theoretical yield x 100
Weight of the of 500ml RB flask before addition of sample: 206.43g
Weight of 500ml RB flask after addition of sample solution: 212.79g
Weight of sample = 212.79 – 206.43 = 6.36g
Theoretical yield is calculated with the aid of a balanced stoichiometry of the reaction.
1. Theoretical yield of methyl salicyl weight of salicylic acid taken: 14g
Moles of salicylic acid: 14.g/138 = 0.10moles
Mass of methanol = Volume of methanol X Density of methanol.
Volume of
INTRODUCTION:
Figure 1: Formation of ester from carboxylic acid.
MECHANISM:
When the carboxylic acid is treated along with the acid catalyst and alcohol[R-OH], It gives rise to the formation of ester along with water. Furthermore alcohol is used in an excess amount in the reaction, because this reaction is probably in equilibrium. Whereas alcohol is employed as a solvent, so it is used quiet larger in the reaction mechanism. Various other acids can also be used as the solvent for the formation of the ester such as sulphuric acid[H2SO4] and tosic acid[TSOH]. In this experiment Methyl salicylates are prepared along with ethyl and 2-propyl salicylates in which the reaction proceeds with salicylic acid as the starting material along with the other reactants such as methanol, ethanol and 2-propanol. More specifically, sulfuric acid is employed as the suitable acid catalyst.
FIGURE 2: Formation of methyl salicylate from salicylic acid.
2. CALCULATION: PERCENTAGE YIELD OF THE PRODUCT: In order to calculate the percentage yield of the product , we need to calculate the theoretical yield. Percentage yield = actual yield/theoretical yield x 100
Weight of the of 500ml RB flask before addition of sample: 206.43g
Weight of 500ml RB flask after addition of sample solution: 212.79g
Weight of sample = 212.79 – 206.43 = 6.36g
Theoretical yield is calculated with the aid of a balanced stoichiometry of the reaction.
1. Theoretical yield of methyl salicyl weight of salicylic acid taken: 14g
Moles of salicylic acid: 14.g/138 = 0.10moles
Mass of methanol = Volume of methanol X Density of methanol.
Volume of