Yield of reactions percent

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  

Problem 0.800 mole of phosphorus was reacted with an excess of sulfur to form diphosphorus pentasulfide, P2S5. 

At the end of the reaction, the actual yield was 82.7 g of P2S5. What is the percent yield of the reaction The molar mass of P2s5 i 222 3 g 

calculate the mass of P2S3 you should obtain from 0.400 mole of phosphorus. This is the theoretical yield of the synthesis. A linked calculation is used. 

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If you answered Incorrectly, review Percent Yield of Reactions, page 209. 

A major disadvantage of this system is the limitation of the single-pass gas-chlorination phase. Unless increased pressure is used, this equipment is unable to achieve higher concentrations of chlorine as an aid to a more complete and controllable reaction with the chlorite ion. The French have developed a variation of this process using a multiple-pass enrichment loop on the chlorinator to achieve a much higher concentration of chlorine and thereby quickly attain the optimum pH for maximum conversion to chlorine dioxide. By using a multiple-pass recirculation system, the chlorine solution concentrates to a level of 5-6 g/1. At this concentration, the pH of the solution reduces to 3.0 and thereby provides the low pH level necessary for efficient chlorine dioxide production. A single pass results in a chlorine concentration in water of about 1 g/1, which produces a pH of 4 to 5. If sodium chlorite solution is added at this pH, only about 60 percent yield of chlorine dioxide is achieved. The remainder is unreacted chlorine (in solution) and... 

Peicent yield. If you started with 20 popcorn kernels, but only 16 of them popped, the percent yield of popcorn from this "reaction would be 16/20 x 100% = 80%. 

TABLE 7.7 Percent Yield of Methylene and Ether Linkages of 2-Hydroxylmethyl-4,6-Dimethylphenol Self-reaction, 1 1 with 2,4-Xylenol, and 1 1 with 2,6-Xylenol... 

If the percent yield of a reaction is already known, we can calculate how much of a product to expect from a synthesis that uses a known amount of starting material. For example, the Haber synthesis of ammonia stops when 13% of the starting materials have formed products. Knowing this, how much ammonia could an industrial producer expect to make from 2.0 metric tons of molecular hydrogen First, calculate the theoretical yield ... 

Silver bromide is a major component of photographic films and paper. A film manufacturer mixed 75.0 L of a 1.25 M solution of silver nitrate with 90.0 L of a 1.50 M potassium bromide solution and obtained 17.0 kg of silver bromide precipitate. What was the percent yield of this precipitation reaction ... 

C04-0067. When HgO is heated, it decomposes into elemental mercuiy and molecular oxygen gas. If 60.0 g of Hg is obtained from 80.0 g of the oxide, what is the percent yield of the reaction ... 

The response factor of the product was determined by preparing a concentration series and analyzing as above using Method 5. The weight percent yield of the cis-1,2/1,4 product as shown in scheme 5 calculated as a function of time and is shown in Table 3 and Figure 16. The product is formed in almost 40% yield within 3 minutes of the start of the reaction. 

For reactions yielding more than one product the percent yield of a particular product can be calculated from the quantum yields of the various reactions ... 

Once we have determined the entropy and enthalpy of polymerization, we can calculate the free energy of the process at a variety of temperatures. The only time this is problematic is when we are working near the temperatures of transition as there are additional entropic and enthalpic effects due to crystallization. From the free energy of polymerization, we can predict the equilibrium constant of the reaction and then use this and Le Chatelier s principle to design our polymerization vessels to maximize the percent yield of our process. 

The limiting reactant is P4, and 111 gPCl3 should be produced. This is the theoretical yield. The actual yield is 104gPCl3. Thus, the percent yield of the reaction is... 

After increasing the solvent to 25 mb, the reaction proceeded quickly at room temperature with a reaction time of 30 min and a percent yield of 77%. 

A 250-mL round-bottomed flask equipped with a water collector (Dean-Stark trap), condenser, and magnetic stirrer is charged with p-H2N(C6H4)NH2 (36 g, 0.33 mol), formic acid (69 mL, 1.8 mol, 3 1 excess), and toluene (80 mL, reagent grade). The mixture is heated to reflux until the water is collected ( 3 h). The flask is cooled, and formamide is collected by hltration, and rinsed with copious amounts of ethanol and diethylether until formic acid is washed away. Color and percent yield of formamide ( 70%) is dependent on the purity of the amine. The reaction can be scaled up, depending on collector size. 

In another recent study of CO reduction using organometallic compounds of the early transition elements, Caulton et al. report that CH4 is evolved when toluene solutions of (C5H5)2Ti(CO)2 are heated at 150°C under H2 or H2 -l- CO atmospheres (55). When deuterium is used, the observed product is CD4, although some deuteration of the cyclopentadienyl rings is noted. Caulton does not report the percent yield of methane, but does state that the reaction is not catalytic. One of the most novel aspects of this investigation is the isolation of a blue Tig cluster that is inert to further reaction... 

Methyl f erf-butyl ether (MTBE, C5H120), a substance used as an octane booster in gasoline, can be made by reaction of isobutylene (C4H8) with methanol (CH40). What is the percent yield of the reaction if 32.8 g of methyl tert-butyl ether is obtained from reaction of 26.3 g of isobutylene with sufficient methanol ... 

Diethyl ether (C4H10O), the "ether" used medically as an anesthetic, is prepared commercially by treatment of ethyl alcohol (C2HfiO) with an acid. How many grams of diethyl ether would you obtain from 40.0 g of ethyl alcohol if the percent yield of the reaction is 87% ... 

PROBLEM 3.9 Ethyl alcohol is prepared industrially by the reaction of ethylene, C2H4, with water. What is the percent yield of the reaction if 4.6 g of ethylene gives 4.7 g of ethyl alcohol ... 

The most common commercial process for the manufacture of vinylidene chloride is the dehydrochlorination of 1,1,2-trichloroethane with lime or caustic in slight excess (2 to 10%). A continuous liquid-phase reaction at 98 to 99°C gives a 90 percent yield of vinylidene. 

Having covered the major components of a chemical reaction, with the exception of energy considerations, the last topic is doing an overall evaluation of a process. There are two straightforward parameters that may be calculated for a reaction that give some indication of efficiency. One is the percent yield of the purified product. The second is atom economy, which was developed by Barry Trost (1991) of Stanford University. Atom economy can be used to determine the fraction of the molecular weight of the reactant(s) incorporated into the product(s). Separate atom economies are calculated for each product of a reaction. 

Further information on the mechanisms of these addition reactions is found in a study of the reaction of "phenylpalladium acetate with trans- and cfs-propenylbenzene 24>. The trans-isomer reacted in nearly quantitative yield at 30 °C in methanol solution to produce trans-1,2-diphenyl-l-propene. About a half of a percent yield of l,2-diphenyl-2-propene was also found. Only a trace of the Markovnikov product 1,1-diphenyl-l-propene was seen (See Chart 1). The reaction of cfs-propenyl-benzene under the same conditions produced an 85% yield of olefins containing 65% of cis- 1,2-diphenyl- 1-propene, 22% trans-1,2-diphenyl-1 -propene, 10% 2,3-diphenyl-l-propene and about 3% of 1,1-diphenyl-1-propene. The major products in both reactions are the one expected from a cis-anti-Markovnikov addition of the phenylpalladium acetate followed by a cis-elimination of "hydrodopalladium acetate . There is practically no Markovnikov addition. 

Calculate the percent yield of a reaction if calculations indicated that 7.44 g of product could be obtained, but only 7.02 g of product was actually obtained. 

C alculate the percent yield of a reaction which produced 36.0 g of C4HgBr2 from 10.0 g of C4H8 and excess Br2. 

The first two reactions have percent yields of 87% and 98% by mass, respectively. The overall reaction yields 3 mol of acetaminophen product for every 4 mol of C6H5O3N reacted. 

You will determine the percent yield of a chemical reaction. 

Chemists need to know how efficient a reaction is in producing the desired product. One way of measuring efficiency is by means of percent yield. Just as you calculated your percent of successful jump shots, a chemist can calculate what percent of the amount of product that could theoretically be produced was actually produced. Percent yield of product is the ratio of the actual yield to the theoretical yield expressed as a percent. 

When copper wire is placed into a silver nitrate solution, silver crystals and copper(ll) nitrate solution form. Write the balanced chemical equation for the reaction. If a 20.0-g sample of copper is used, determine the theoretical yield of silver. If 60.0 g silver is actually recovered from the reaction, determine the percent yield of the reaction. 

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