La fórmula empírica es una expresión o forma que representa la proporción más simple en la que están presentes los átomos que forman un compuesto químico, en ella se relacionan los símbolos de los elementos con un número entero correspondiente a cada símbolo. Puede coincidir o no con la fórmula molecular, que indica el número de átomos presentes en la molécula.
Determinación experimental de fórmulas empíricas.
1. El análisis químico indica el numero de gramos de cada elemente presentes en una determinada cantidad de un compuesto.
2. Las cantidades de gramos se convierten a moles de cada elemento, recuerde que para convertir moles a gramos es necesario utilizar el peso atómico del elemento.
3. Seguidamente se debe realizar una comparación entre las moles obtenidas a fin de determinar la de menor valor.
4. Por último las moles de los demás elementos deben ser divididas por el número de moles de menor valor escogido en el numeral anterior. El cociente de esta división debe ser un numero entero, en caso contrario debe aproximarse (siempre y cuando sea posible) al valor entero más cercano o por ensayo y error determinar un numero entero que multiplique a todos los cocientes y los convierta en valores enteros. Una vez realizado este procedimiento se escribe la formula empírica con lo cocientes determinados para cada elemento.
Ejemplo 3.
La alicina es el compuesto responsable del olor característico del ajo. Un análisis de dicho compuesto muestra la siguiente composición porcentual en masa: C: 44,4%; H: 6,21%; S: 39,5%; O: 9,86%. Calcule su fórmula empírica.
Solución:
Se inicia suponiendo que hay 100 gramos de compuesto en este caso alicina, de tal manera que:
Una vez obtenidos los moles de cada elemento se procede a realizar la división de cada uno de ellos entre las moles de menor valor que en este caso corresponden al oxígeno a fin de hallar los cocientes para escribir de la formula empírica:
Formula empírica: C6H10S2O
Determinación de Formulas Moleculares
Para calcular la fórmula molecular, o real, se requiere conocer la masa molecular aproximada del compuesto, además de su formula empírica. Conociendo que el peso molecular de un compuesto debe ser un múltiplo entero (n) del peso molecular de la fórmula empírica. Por tanto,
(Peso Molecular de la Formula Empírica)*n = (Peso Molecular de la Fórmula Molecular)
Ejemplo 4.
Determinar la formula molecular de la alicina (ejemplo 3), sabiendo que el peso molecular de su formula molecular es 120g/mol.
Peso molecular de la Formula empírica:
C = 12g x 3 = 36g/mol
H = 1g x 10 = 10g/mol
S = 32g x 2 = 64g/mol
O = 16g x 1 = 16g/mol
Peso Molecular = 120g/mol
25 comentarios:
hola como estás, la verdad que es espectacular la explicación, te felicito, pero quiero hacer una puntualización, cuando estás calculando la formula molecular, multiplicas el peso atómico del carbono por 3, y en realidad es por 6, esto cambiaría el restado y no sería 120g sino que sería 162g, igualmente la formula molecular es la misma que la empírica... demás está excelente, muchos profesores debería aplicar la técnica que tu usaste.. TE FELICITO !!!
n = Pm compuesto/ Pm formula empirica
Lo que multiplica a la incógnita pasa a dividir.
36+10+64+16= 126
Really great blog, it's very helpful and has great knowledgeable information.
Best Online Training institute
SE DEBE CORREGIR EL ERROR DE LA MASA MOLECULAR QUE ES 162g/mol-g
Sii...hay un error...el peso de la formula empírica da 162 ...al dividir 120 entre 162 da 0.7...esta cifra se aproxima a 1?
QuickBooks has made payroll management quite definitely easier for accounting professionals. There are plenty people that are giving QuickBooks Payroll Support Phone Number once they process payroll either QB desktop and online options.
There can be occasions as soon as you might face some form of delay in reaching us, let’s say during the time of filing taxes because there is a lot of hush-hush then. We assure you that folks will revert for you personally in less time and work out us accessible to you at QuickBooks Support Number
By using QuickBooks Payroll Contact Phone Number
, you're able to create employee payment on time. However in any case, you might be facing some problem when making use of QuickBooks payroll such as for instance issue during installation, data integration error, direct deposit issue, file taxes, and paychecks errors, installation or up-gradation or simply just about some other than you don’t panic, we provide quality QuickBooks Payroll help service. Here are some features handle by our QB online payroll service.
Our support, as covered by QuickBooks Enterprise Tech Experts at, includes all the functional and technical aspects linked to the QuickBooks Enterprise Support Number They include all QuickBooks errors encountered during the running of QuickBooks Enterprise and all issues faced during Installation, update, additionally the backup of QB Enterprise.
All the above has a certain use. People working with accounts, transaction, banking transaction need our service. Some of you are employing excel sheets for a few calculations. But, this sheet cannot calculate accurately the figures. This becomes one of many primary good reasons for poor cashflow management in lot of businesses. It will be the time for QuickBooks Payroll Support Phone Number. The traders can’t make money. But, we have been here to support a forecast.
All of us can be obtained 24*7 to provide the most recent news, helpful tips, training and consulting services to all the its clients. All of these resources definitely show to be fruitful for you personally. Just in case, you get stuck at any point, make a call at our QuickBooks Technical Support Phone Number.
Give a call at QuickBooks Technical Support Number, if you are encountering any difficulties which are mentioned above. If you are facing some other problems with your QuickBooks, you'll be able to also make instant calls. Your queries are certain to get resolved without the delays.
The experts at our QuickBooks Enterprise Support have the necessary experience and expertise to address all issues linked to the functionality associated with the QuickBooks Enterprise.
We make sure that your calls aren't getting bounced. In case your calls are failing continually to relate to us at QuickBooks Tech Support Phone Number then you can also join all of us by dropping a contact without feeling shy. Our customer service support will stay available even in the wee hours.
It Will Makes Your Bank Account Job Easy And A Lot Of Important, It's Not Complicated, And Yes It Really Is An Undeniable Fact. QuickBooks Enterprise Technical Support Is Obviously One The Most Consistent Enterprise Software, Its Recent Version QuickBooks Enterprise 2018.
We provide you with the best and amazing services about QuickBooks and also provides you various types of information and guidance regarding your errors or issues in just operating the best QuickBooks Tech Support Phone Number software.
You can actually resolve this error by using the below troubleshooting steps you can simply contact our QuickBooks Support Phone Number available at.You should run QuickBooks Support Phone Number print and pdf repair tool to ascertain and fix the errors in printer settings before you start the troubleshooting.
That is completely a toll-free QuickBooks Tech Support Phone Number client Service variety that you won’t pay any call charges. Needless to say, QuickBooks is one the large choice of awesome package within the company world.
It is possible to rest assured; most of the QuickBooks Customer Service and problems are handled because of the simplest in business. Our specialists could possibly get to figure on the drawback at once. this is often why we have a tendency to square measure recognized for our client Support services.
In the event of errors, to gain access to the expert services, dial QuickBooks Support Tech Support and also for the application, head to Loan Supervisor, to the Banking menu.
Our moral when it comes to troubleshooting is that no issue is too small, and no query is unimportant. No one understands that better than us. Like anyone, we know that everyone has to start somewhere and somehow. This understanding and state of mind are what drives our support team to treat your question with the utmost amount of severity. All the information that you require will be provided to you once you contact the QuickBooks Support. Whether that may be smooth navigation through the software on your own terms or starting from a being a novice in dealing with errors to advanced error handling. All of it is just a click away. Call today for our toll-free services.
Our QuickBooks Tech Support Phone Number customer service is present for you at any time. Speak to us simply by using an unknown number or email indicated regarding the Quickbooks Support site. We will be thrilled to help you with any question about QuickBooks it's likely you have.
QuickBooks Payroll Technical Support Number is an accounting, cloud-based software, founded by Inuit Inc. This has aimed when it comes to highest pedestal in managing accurate financial records for many form of business.
QB mistake 9999 can happen while you are introducing a program or Intuit Inc. related programming program (for example QuickBooks) is running. If you would like to learn How To Troubleshoot Quickbooks Error 9999, you can continue reading this blog.
Publicar un comentario