Yield, actual theoretical

Percent yield [(actual/theoretical) X 100%] is a measure of the efficiency of a chemical reaction. 

The theoretical yield of a reaction is the maximum quantity (amount, mass, or volume) of product that can be obtained from a given quantity of reactant. The quantities of products calculated from a given mass of reactant in Section L were all theoretical yields. The percentage yield is the fraction of the theoretical yield actually produced, expressed as a percentage ... 

In a 5-I. round-bottom flask, fitted with a mechanical stirrer and reflux condenser, are mixed 1150 cc. of water, 840 cc. of commercial sulfuric acid and 700 g. of benzyl cyanide (preparation III, p. 9). The mixture is heated under a reflux condenser and stirred for three hours, cooled slightly and then poured into 2 1. of cold water. The mixture should be stirred so that a solid cake is not formed the phenylacetic acid is then filtered off. This crude material should be melted under water and washed by decantation several times with hot water. These washings, on cooling, deposit a small amount of phenylacetic acid which is filtered off and added to the main portion of material. The last of the hot water is poured off from the material while it is still molten and it is then transferred to a 2-1. Claisen distilling flask and distilled in vacuo. A small amount of water comes over first and is rejected about 20 cc., containing an appreciable amount of benzyl cyanide, then distils. This fraction is used in the next run. The distillate boiling i76-i89°/5o mm. is collected separately and solidifies on standing. It is practically pure phenylacetic acid, m. p. 76-76.5° it amounts to 630 g. (77.5 per cent of the theoretical amount). As the fraction which is returned to the second run of material contains a considerable portion of phenylacetic acid, the yield actually amounts to at least 80 per cent. 

The percentage yield is the fraction of the theoretical yield actually produced, expressed as a percentage ... 

The theoretical yield of a product is the maximum mass, amount, or volume that can be expected on the basis of the stoichiometry of a chemical equation. The percentage yield is the percentage of the theoretical yield actually achieved. 

The actual yield and theoretical yield at appropriate steps of processing. 

Batch Reconciliation and Label Reconciliation Theoretical Yield Actual Yield Packaged Yield... 

The amounts of products calculated in the stoichiometric problems so far represent theoretical yields. The theoretical yield is the maximum amount of product that can be produced from a given amount of reactant. In most chemical reactions, the amount of product obtained from a reaction is less than the theoretical yield. The measured amount of a product that is obtained from a reaction is called the actual yield of that product. 

Chemists are usually interested in the efficiency of a reaction. The efficiency is expressed by comparing the actual yield to the theoretical yield. The percent yield is the ratio of actual yield to theoretical yield multiplied by 100 percent. 

Why Actual Yield and Theoretical Yield Are Often Different... 

Since the DGEBA/DDS networks are tetrafunctional and of stoichiometric composition, the theoretical value of z is 2. Furthermore, the crosslink concentration, c, is simply the DDS molecule concentration. Performing the necessary calculations yields the theoretical M, listed in Table 4. Compared to the experimental M, the theoretical values are very consistent. If it is assumed that the DGEBA/DDS networks are not phantom-like (i.e., A = 1), then the ratio of the theoretical and experimental values may serve as an estimate of the dilation factor, These ratios are listed in Table 4, and show that is approximately unity for all the networks. If the experimental M had been calculated using the actual network densities (instead of q = 1 g/cm), the ratios would be even closer to unity, being reduced by approximately 20 percent. 

A total of 310.3 g of methyl ester were pyrolysed to yield 204.4 g of liquid product which corresponds to a 65.9% actual liquid yield. The theoretical yield based on a typical Cie, C composition of soybean oil, and the y-hydrogen transfer mechanism is approximately 76%. Therefore, the yield based on this limitation is approximately 87%. "niis shows that random cracking of the ester chain does not play a significant role in the reaction. The infrared spectrum shows no carbonyl peaks at 1720 cm. Peaks appearing at 907 cm" and 965 cm arc probably absorptions due to terminal alkenes and trans alkenes, otherwise the spectrum looks like that of a typical alkane. Consistent with these results, elemental analysis gave 83.7% carbon, 14.56%... 

The ratio of actual yield to theoretical yield, multiplied by 100%, gives the percentage yield of zinc ... 

The amount of product produced when a reaction runs to completion is called the theoretical yield. The amount of actual product after a real experiment is the actual yield. As mentioned above, reactions often don t run to completion, and sometimes there are competing reactions that reduce the actual yield. Actual yield divided by the theoretical yield, times 100, gives the percent yield. 

Percent yield = actual yield ioo% theoretical yield... 

Percentage yield = (actual yield/theoretical yield) x 100... 

The theoretical yield of a reaction is the calculated amount of product that should be obtained in a reaction. But in practice, something less than the theoretical yield, the actual yield, is obtained. For many reasons—impure reagents, solubility problems, decomposition, or spillage—the amount of product isolated from a reaction is frequently less than that calculated from the balanced equation. The fraction of the theoretical yield actually obtained in a reaction is expressed as the percent yield of the reaction. 

The actual yield and theoretical yield should be given in the same units grams, moles, and so on. Suppose in a synthesis reaction you calculated that you should obtain 50.0 grams of product, the theoretical yield. But when you did the reaction you only obtained 45.5 grams. The percent yield would be ... 

Theoretical yield, actual yield, and percent yield (page 209) ... 

Comparison of actual yield vs., theoretical yield at each manufacturing step. 

This is the theoretical yield of Li3N. The actual yield is given in the problem (5.89 g). The percent yield is % yield = actual yield 5 ... 

Your text talks about several sorts of "yield" when experiments are performed in the laboratory. Students often confuse these terms. Define, compare, and contrast what are meant by theoretical yield, actual yield, and percent yield. 

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