The reaction for the industrial production of hydrogen cyanide is given below.
2CH4 + 2NH3 + 3O2 --> 2HCN + 6H2O
What mass of NH3 is required for the synthesis of 1.5 × 105 kg of HCN if the reaction has a 97.5% yield?
Stoichiometry 101.
2CH4 + 2NH3 + 3O2 --> 2HCN + 6H2O
What mass of NH3 is required for the synthesis of 1.5 × 105 kg of HCN if the reaction has a 97.5% yield?
mols HCN = 150,000g/molar mass HCN = ?
Using the coefficients in the balanced equation, convert mols HCN to mols NH3. That will be ?mols HCN x (2 mols NH3/2 mols HCN) or ?mols HCN = same mols NH3.
Now convert mols NH3 to grams. grams NH3 = mols NH3 x molar mass NH3. This assumes 100% yield. The problem gives yield at 97.5%. You will want (g @ 100% yield/0.0975) = grams at 97.5% yield.
Yeah thank you, but i still can't figure it out :(
Well, let's do some calculations, shall we? We have the balanced equation for the reaction, so that's a good start. We need to find the mass of NH3 required.
First, we need to calculate the molar mass of NH3, which is approximately 17 g/mol. Now, let's figure out how many moles of HCN we have, considering the given mass of 1.5 × 10^5 kg.
Mass of HCN = 1.5 × 10^5 kg
Molar mass of HCN = 27 g/mol
Using the molar mass, we can find the number of moles of HCN:
Number of moles of HCN = Mass of HCN / Molar mass of HCN
= (1.5 × 10^5 kg * 1000 g/kg) / 27 g/mol
≈ 5.56 × 10^6 mol
Now, since the reaction has a 97.5% yield, we have to adjust our calculations accordingly. Since the yield is given as a percentage, we can calculate the actual amount of HCN produced:
Actual moles of HCN produced = Number of moles of HCN * Yield
= 5.56 × 10^6 mol * 0.975
≈ 5.41 × 10^6 mol
According to the balanced equation, 2 moles of NH3 are required for the production of 2 moles of HCN. Therefore, the molar ratio between NH3 and HCN is 1:1.
Hence, the mass of NH3 required can be calculated as:
Mass of NH3 required = Molar mass of NH3 * Actual moles of HCN produced
= 17 g/mol * 5.41 × 10^6 mol
≈ 9.2 × 10^7 g
So, approximately 92,000,000 grams (or about 92,000 kilograms) of NH3 are required for the synthesis of 1.5 × 10^5 kg of HCN, given a 97.5% yield. And I thought clown noses were big!
To find the mass of NH3 required for the synthesis of 1.5 × 105 kg of HCN, we need to use stoichiometry and the given balanced equation. Here's how you can calculate it:
Step 1: Determine the molar mass of NH3 (Ammonia):
The molar mass of NH3 is calculated by adding up the atomic masses of its constituent elements.
Molar mass of N = 14.01 g/mol
Molar mass of H = 1.01 g/mol
Therefore, molar mass of NH3 = (1.01 g/mol) + (3 × 1.01 g/mol) = 17.03 g/mol
Step 2: Calculate the number of moles of HCN produced:
Mass of HCN = 1.5 × 105 kg
To convert this into grams, multiply by 1000:
Mass of HCN = 1.5 × 105 kg × 1000 g/kg = 1.5 × 108 g
Now, calculate the number of moles of HCN using its molar mass:
Molar mass of HCN = 27.03 g/mol (calculated from the balanced equation)
Number of moles of HCN = Mass of HCN / Molar mass of HCN
Number of moles of HCN = (1.5 × 108 g) / (27.03 g/mol)
Step 3: Adjust the moles of NH3 based on the stoichiometry of the reaction:
From the balanced equation, we can see that:
2 moles of CH4 react with 2 moles of NH3 to produce 2 moles of HCN.
Therefore, the molar ratio between NH3 and HCN is 2:2, which simplifies to 1:1.
So, the number of moles of NH3 required will be the same as the number of moles of HCN produced.
Step 4: Calculate the mass of NH3 required:
Number of moles of NH3 required = Number of moles of HCN
Mass of NH3 required = Number of moles of NH3 required × Molar mass of NH3
Now, using the information provided in the question, we can find the mass of NH3 required.
Note: You mentioned that the reaction has a 97.5% yield. This means that only 97.5% of the intended product (HCN) is obtained. To account for this yield, we need to divide the mass of HCN calculated above by the yield to determine the actual mass of NH3 required.
Final Step: Calculate the mass of NH3 required accounting for the yield:
Mass of NH3 required = (Mass of HCN) / (Yield)
Substitute the values into the equation:
Mass of NH3 required = (1.5 × 108 g) / (27.03 g/mol) / (0.975)
Now, calculate the result to find the mass of NH3 required.
Okay so first up you have to figure out what the definitions are. Here is a little help.
Hydrogen cyanide (HCN), sometimes called prussic acid, is an organic compound[8] with the chemical formula HCN. It is a colorless, extremely poisonous and flammable liquid that boils slightly above room temperature, at 25.6 °C (78.1 °F).[9] HCN is produced on an industrial scale and is a highly valuable precursor to many chemical compounds ranging from polymers to pharmaceuticals.
Hydrogen cyanide is weakly acidic with a pKa of 9.2. It partly ionizes in water solution to give the cyanide anion, CN–. A solution of hydrogen cyanide in water is called hydrocyanic acid. The salts of hydrogen cyanide are known as cyanides. HCN has a faint, bitter, burnt almond-like odor that some people are unable to detect due to a genetic trait.[2] The volatile compound has been used as inhalation rodenticide and human poison. Cyanide ions interfere with iron-containing respiratory enzymes. HCN is produced on an industrial scale, and is a highly valuable precursor to many chemical compounds, ranging from polymers to pharmaceuticals.
Hydrogen cyanide was first isolated from a blue dye (Prussian blue) which had been known from 1704 but had a structure which was unknown. It is now known to be a coordination polymer with a complex structure and an empirical formula of hydrated ferric ferrocyanide. In 1752, the French chemist Pierre Macquer made the important step of showing that Prussian blue could be converted to iron oxide plus a volatile component and that these could be used to reconstitute the dye. The new component was what we now know as hydrogen cyanide. Following Macquer's lead, it wa isolated from Prussian blue in pure form and characterized about 1783 by the Swedish chemist Carl Wilhelm Scheele, and was eventually given the German name Blausäure (literally "Blue acid") because of its acidic nature in water and its derivation from Prussian blue. In English it became known popularly as Prussic acid.
In 1787 the French chemist Claude Louis Berthollet showed that Prussic acid did not contain oxygen, an important contribution to acid theory, which had hitherto postulated that acids must contain oxygen[3] (hence the name of oxygen itself, which is derived from Greek elements that mean "acidformer" and are likewise calqued into German as Sauerstoff). In 1815 Joseph Louis Gay-Lussac deduced Prussic acid's chemical formula. The radical cyanide in hydrogen cyanide was given its name from the Greek word for blue, again due to its derivation from Prussian blue.
Hydrogen cyanide forms in at least limited amounts from many combinations of hydrogen, carbon, and ammonia. Hydrogen cyanide is currently produced in great quantities by several processes, as well as being a recovered waste product from the manufacture of acrylonitrile.[4] In the year 2000, 732,552 tons were produced in the US.[5] The most important process is the Andrussov oxidation invented by Leonid Andrussow at IG Farben in which methane and ammonia react in the presence of oxygen at about 1200 °C over a platinum catalyst:[6] 2 CH4 + 2 NH3 + 3 O2 → 2 HCN + 6 H2O The energy needed for the reaction is provided by the partial oxidation of methane and ammonia. Of lesser importance is the Degussa process (BMA process) in which no oxygen is added and the energy must be transferred indirectly through the reactor wall:[7] CH4 + NH3 → HCN + 3H2 This reaction is akin to steam reforming, the reaction of methane and water to give carbon monoxide and hydrogen. In the Shawinigan Process, ammonia and natural gas are passed over coke. As practiced at BASF, formamide is heated and split into hydrogen cyanide and water: CH(O)NH2 → HCN + H2O In the laboratory, small amounts of HCN are produced by the addition of acids to cyanide salts of alkali metals: H+ + NaCN → HCN + Na+ This reaction is sometimes the basis of accidental poisonings because the acid converts a nonvolatile cyanide salt into the gaseous HCN. Historical methods of production The demand for cyanides for mining operations in the 1890s was met by George Thomas Beilby, who patented a method to produce hydrogen cyanide by passing ammonia over glowing coal in 1892. This method was used until Hamilton Castner in 1894 developed a synthesis starting from coal, ammonia, and sodium yielding sodium cyanide, which reacts with acid to form gaseous HCN. Applications See also: sodium cyanide HCN is the precursor to sodium cyanide and potassium cyanide, which are used mainly in mining. Via the intermediacy of cyanohydrins, a variety of useful organic compounds are prepared from HCN including the monomer methyl methacrylate, from acetone, the amino acid methionine, via the Strecker synthesis, and the chelating agents EDTA and NTA. Via the hydrocyanation process, HCN is added to butadiene to give adiponitrile, a precursor to Nylon 66.[4]
Hydrogen cyanide - Wikipedia, the free encyclopedia
3 of 7 6/3/10 6:07 PM
Occurrence HCN is obtainable from fruits that have a pit, such as cherries, apricots, apples, and bitter almonds, from which almond oil and flavoring are made. Many of these pits contain small amounts of cyanohydrins such as mandelonitrile and amygdalin, which slowly release hydrogen cyanide.[8][9] One hundred grams of crushed apple seeds can yield about 10 mg of HCN.[citation needed] Some millipedes release hydrogen cyanide as a defense mechanism,[10] as do certain insects such as some burnet moths. Hydrogen cyanide is contained in the exhaust of vehicles, in tobacco and wood smoke, and in smoke from burning nitrogen-containing plastics. So-called "bitter" roots of the cassava plant may contain up to 1 gram of HCN per kilogram.[11][12] HCN and the origin of life Hydrogen cyanide has been discussed as a precursor to amino acids and nucleic acids. It is possible, for example, that HCN played a part in the origin of life.[13] Although the relationship of these chemical reactions to the origin of life remains speculative, studies in this area have led to discoveries of new pathways to organic compounds derived from condensation of HCN.[14] HCN in space See also: Astrochemistry HCN has been detected in the interstellar medium.[15] Since then, extensive studies have probed formation and destruction pathways of HCN in various environments and examined its use as a tracer for a variety of astronomical species and processes. HCN can be observed from ground-based telescopes through a number of atmospheric windows.[citation needed] The J=1→0, J=3→2, J= 4→3, and J=10→9 pure rotational transitions have all been observed.[15][16][17] HCN is formed in interstellar clouds through one of two major pathways:[18] via a neutral-neutral reaction (CH2 + N → HCN + H) and via dissociative recombination (HCNH+ + e- → HCN + H). The dissociative recombination pathway is dominant by 30%; however, the HCNH+ must be in its linear form. Dissociative recombination with its structural isomer, H2NC+ produces hydrogen isocyanide (HNC), exclusively. HCN is destroyed in interstellar clouds through a number of mechanisms depending on the location in the cloud.[18] In photon-dominated regions (PDRs), photodissociation dominates, producing CN (HCN + ν → CN + H). At further depths, photodissociation by cosmic rays dominate, producing CN (HCN + cr → CN + H). In the dark core, two competing mechanisms destroy it, forming HCN+ and HCNH+ (HCN + H+ → HCN+ + H; HCN + HCO+ → HCNH+ + CO). The reaction with HCO+ dominates by a factor of ~3.5. HCN has been used to analyze a variety of species and processes in the interstellar medium. It has been suggested as a tracer for dense molecular gas[19][20] and as a tracer of stellar inflow in high-mass star-forming regions[21]. Further, the HNC/HCN ratio has been shown to be an excellent method for distinguishing between PDRs and X-ray-dominated regions (XDRs).[22]
Hydrogen cyanide - Wikipedia, the free encyclopedia
4 of 7 6/3/10 6:07 PM
Hydrogen cyanide as a poison and chemical weapon See also: cyanide poisoning A hydrogen cyanide concentration of 300 mg/m3 in air will kill a human within about 10 minutes. It is estimated that hydrogen cyanide at a concentration of 3500 ppm (about 3200 mg/m3) will kill a human in about 1 minute. The toxicity is caused by the cyanide ion, which halts cellular respiration by inhibiting an enzyme in mitochondria called cytochrome c oxidase. Hydrogen cyanide absorbed into a carrier for use as a pesticide (under IG Farben's brand name Cyclone B, or in German Zyklon B, with the B standing for Blausäure)[23] was most infamously employed by Nazi Germany in the mid-20th century in extermination camps. The same product is currently made in the Czech Republic under the trademark "Uragan D1." Hydrogen cyanide is also the agent used in gas chambers employed in judicial execution in some U.S. states, where it is produced during the execution by the action of sulfuric acid on an egg-sized mass of potassium cyanide. Hydrogen cyanide is commonly listed amongst chemical warfare agents that cause general poisoning and skin blisters.[24] As a substance listed under Schedule 3 of the Chemical Weapons Convention as a potential weapon which has large-scale industrial uses, manufacturing plants in signatory countries which produce more than 30 tonnes per year must be declared to, and can be inspected by, the Organisation for the Prohibition of Chemical Weapons. Under the name prussic acid, HCN has been used as a killing agent in whaling harpoons.[25] Hydrogen cyanide gas in air is explosive at concentrations over 5.6%, equivalent to 56000 ppm[26].
Hopefully this helped you out, and if you need more info, just look it up on wiki or other sites! Good luck, and if you cant figure it out still, comment and I will give you the answer to the problem! :)