Grams reactant

To decide which component should be employed for the calculation of the yield of ethyl iodide, the weights of the reactants are first divided by the appropriate atomic or molecular weight in order to obtain the number of gram atoms or gram mols actually used. The equation shows that the alcohol and iodine react in the ratio of 5 5 or 1 1. Inspection of the results clearly shows that the alcohol is present in about 20 per... 

For the aqueous solution Place 16mL of cool distilled water into your bubbler setup. The "expected, not theoretical, yield of Methylamine from this amount of reactants is 7 grams. I have used a plastic aquarium aerator tube as the bubbler with excellent results. Sure beats using an inverted funnel. 

The quantities of reactants and products are expressed in grams, the figures in parentheses are the yields in mole per mole of benzoyl peroxide. 

A comparison of the characteristics associated with propellant burning, explosive detonation, and the performance of conventional fuels (see Coal Gas, NATURAL Petroleum) is shown ia Table 1. The most notable difference is the rate at which energy is evolved. The energy Hberated by explosives and propellants depends on the thermochemical properties of the reactants. As a rough rule of thumb, these materials yield about 1000 cm of gas and 4.2 kj (1000 cal) of heat per gram of material. 

A few industrial catalysts have simple compositions, but the typical catalyst is a complex composite made up of several components, illustrated schematically in Figure 9 by a catalyst for ethylene oxidation. Often it consists largely of a porous support or carrier, with the catalyticaHy active components dispersed on the support surface. For example, petroleum refining catalysts used for reforming of naphtha have about 1 wt% Pt and Re on the surface of a transition alumina such as y-Al203 that has a surface area of several hundred square meters per gram. The expensive metal is dispersed as minute particles or clusters so that a large fraction of the atoms are exposed at the surface and accessible to reactants (see Catalysts, supported). 

Thereafter, the ammonia was evaporated, 1 liter of water was added thereto and the aqueous phase was separated and extracted with ether. The ethereal phases now combined were washed with water until the wash waters were neutral, then dried over sodium sulfate, filtered and distilled to dryness to obtain 21 grams of product, which was dissolved in 210 cc of ethanol under reflux. Next, 21 cc of acetic acid and 21 grams of Girard s reactant T were added thereto. The mixture was agitated for hours under an atmosphere of nitrogen while maintaining the reflux. Thereafter, the reaction mixture was cooled to room temperature and then poured into 1,050 cc of water. Next, 155 cc of 2 N sodium hydroxide solution were added and finally the mixture was extracted with ether. 

Stage 1 Preparation of 2-Phenyl-2-Methoxy-Ethyl Bromide - 1.3 mols of tert-butyl hypo-bromite is added slowly and with agitation to a mixture of 107 grams (1 mol) of vinyi-benzene (styrene) and 250 mi of methanol (99%), kept at -10°C. When the addition of the reactant is finished, the mixture is allowed to return to ambient temperature, it is washed in water and dried on anhydrous NajS04. Rectification is effected in vacuo in order to obtain a colorless liquid BP,j = 113°C, BPj.j = 84°C, = 1,5429, yield = 76%. 

A mixture of 103.6 grams (0.6 mol) of the freshly prepared potassium enolate of ethyl fluoromalonaldehydate, 83.4 grams (0.3 mol) of S-methylisothiouronium sulfate and 32.5 grams (0.6 mol) of sodium methoxide was refluxed with stirring in 1,500 ml of absolute methanol. At first the reactants dissolved to a great extent, but very shortly thereafter precipitation occurred. The reaction mixture was refluxed for 2 hours and at the end of this time was evaporated to dryness in vacuo. The residue was treated with 280 ml of water incomplete dissolution was observed. 

Preparation of J-Sulfanilamido-S-Methylisoxazole 2 grams of 3-acetylsulfanilamido-5-methylisoxazole was heated with 10 cc of an aqueous sodium hydroxide solution on a water-bath for one hour and after cooling the reactant was acidified by addition of acetic acid. The precipitate thus formed was recrystallized from dilute alcohol to give 15 grams of colorless prisms of 3-sulfanilamido-5-methylisoxazole, melting point 167°C. 

One molecule (or mole) of propane reacts with five molecules (or moles) of oxygen to produce three molecules (or moles) or carbon dioxide and four molecules (or moles) of water. These numbers are called stoichiometric coefficients (v.) of the reaction and are shown below each reactant and product in the equation. In a stoichiometrically balanced equation, the total number of atoms of each constituent element in the reactants must be the same as that in the products. Thus, there are three atoms of C, eight atoms of H, and ten atoms of O on either side of the equation. This indicates that the compositions expressed in gram-atoms of elements remain unaltered during a chemical reaction. This is a consequence of the principle of conservation of mass applied to an isolated reactive system. It is also true that the combined mass of reactants is always equal to the combined mass of products in a chemical reaction, but the same is not generally valid for the total number of moles. To achieve equality on a molar basis, the sum of the stoichiometric coefficients for the reactants must equal the sum of v. for the products. Definitions of certain terms bearing relevance to reactive systems will follow next. 

A student is told to prepare 45.0 g of aspirin. She is also told to use a 55.0% excess of acetic anhydride and to expect to get an 85.0% yield in the reaction. How many grams of each reactant should she use ... 

Strategy Start by writing a balanced chemical equation for the reaction involved. Then use Equation 17.1 in combination with Table 17.1 to calculate the difference in entropy between products and reactants. For (b) note that you are asked to calculate AS° for one gram of methane. 

Strategy This problem is entirely analogous to Example 19.4. First, find Am for the equation as written, and then find Am for one gram of reactant. Finally, calculate A AE = 9.00 X 1010 kj/g X Am. 

Reality Check Comparing the answers to (a) and (b), it appears that the fusion reaction produces about seven times as much energy per gram of reactant (57.2 X 107 versus 8.19 X 107 kj) as does the fission reaction. This factor varies from about 3 to 10, depending on the particular reactions chosen to represent the fusion and fission processes. 

After reaction, the activity of a 25.0-mL water sample is 745 counts per minute (cpm), caused by the presence of Tl+-204 ions. The activity of Tl-204 is 5.53 X 105 cpm per gram of thallium metal. Assuming that 02 is the limiting reactant in the above equation, calculate its concentration in moles per liter. 

The equation for a chemical reaction speaks in terms of molecules or of moles. It contains the basis for stoichiometric calculations. However, in the laboratory a chemist measures amounts in such units as grams and milliliters. The first step in any quantitative calculation, then, is to convert the measured amounts to moles. In mole units, the balanced reaction connects quantities of reactants and products. Finally, the result is expressed in the desired units (which may not necessarily be the same as the original units). 

Twenty-four grams (0.11 mole) of red mercuric oxide (Note 1) and 60 ml. of freshly distilled 1,1,2,2-tetrachloroethane are placed in a 250-ml. three-necked flask equipped with a dropping funnel, a reflux condenser, and a stirrer. A solution of 32.2 g. (0.20 mole) of bromine and 17.2 g. (0.20 mole) of cyclopropanecarboxylic acid in SO ml. of tetrachloroethane is added dropwise to the stirred suspension of mercuric oxide over a period of 45 minutes, the flask being kept in a water bath at 30-35° (Note 2). The mixture is stirred after the addition of the reactants until the evolution of carbon dioxide ceases. 

Thus, a polyester sample (1-3 g, exactly weighed) is dissolved in 25 mL of a titrated solution of acetic anhydride in dry pyridine (10% mass). The solution is heated to reflux for 1 h. After cooling, 50 mL pyridine and 10 mL water are added. The excess acetic acid present in the resulting solution is titrated by aqueous potassium hydroxide (0.5 mol/L) using a potentiometric titrator. The determination must be carried out in duplicate and a blank titration must be performed under the same conditions. The mass of polyester and the concentration of reactants should be adjusted to ensure that at least a fourfold excess of acetic anhydride is used. The final result (OH content) is expressed in mmol OH/g polyester or as the hydroxyl number, defined as the number of milligrams of KOH required to neutralize the acetic acid consumed per gram of polyester. [Hydroxyl number = (number of mmol OH/g polyester) x 56.106.]... 

To find out the mass of a product that can be formed from a known mass of a reactant, we first convert the grams of reactant into moles, use the mole ratio from the balanced equation, and then convert the moles of product formed into grams. Essentially, we go through three steps ... 

It is convenient to express the rate constants in units of gram equivalents of the reacting functional group (COOH in this case) per liter, rather than in moles of the reactant per liter as is customary this scheme has been adopted in Table V. Then the rate of the first and second steps may be written, respectively... 

Table 3), Enantioselective reaction was of order 0 7 in hydrogen by the initial rate method (over the range 2 to 50 bar, 293 K, cinchonine modifier) and 0 2 in pyruvate (0 1 to 3.0 M, 293 K, 10 bar pressure, cinchonine modifier) Enantiomeric excess was independent of reactant concentrations within these ranges Reactions exhibited self-poisoning so that complete conversion was not achieved within 20 h reaction time. As the quantity of cinchonine modifier added to the catalyst was increased from zero to 1 gram per gram so the... 

The occurrence of pore diffusion can usually be determined by simply grinding the catalyst into smaller and smaller particles. If the rate per gram of catalyst increases as the particles become smaller and smaller, then pore diffusion is likely to be occurring. This effect is due to the fact that the pore lengths are decreased by the catalyst particles being ground into smaller and smaller pieces. Eventually, the pores become short enough that the reactants can readily diffuse in and out of them faster than the chemical reaction occurs on the surface. 

This problem gives the quantities of the two reactants in grams we must first change them to moles ... 

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