Methane Stoichiometry

[Vultux]

Methane is a very powerful greenhouse gas. One pound of methane traps 25 times more heat in the atmosphere than a pound of carbon dioxide. Methane is also the main ingredient in natural gas. Because methane can be captured from landfills, it can be burned to produce electricity, heat buildings, or power garbage trucks. What volume of oxygen is necessary to completely react with 8.46 x 1019 molecules of methane gas, CH4 during combustion?

So I started with balancing the equation, which is CH4 + 2O2 -> CO2 + 2H2O

So I solved this which is 6.3 * 10^-3.

^{Now I need help with this part: "If the reactant in the least amount were to be quadrupled, how many grams of each product would be made?"}

^{Any help is appreciated}

Edited February 15, 2017 by Vultux

[hypervalent_iodine]

I'm not able to check your answer presently, but I'll assume it's correct for now. Where exactly are you struggling in the next part? Have you identified which reactant is in the least amount? What would happen if you quadrupled it?

 

To be honest, the question seems a bit silly. Is there any other information given or does it follow directly from the question you posted?

[Daecon]

Is it something to do with working out the mole units?

Edited February 15, 2017 by Daecon

[Vultux]

I'm not able to check your answer presently, but I'll assume it's correct for now. Where exactly are you struggling in the next part? Have you identified which reactant is in the least amount? What would happen if you quadrupled it?

 

To be honest, the question seems a bit silly. Is there any other information given or does it follow directly from the question you posted?

I have no idea how to find the limiting reagent. Not really, teacher gave this as a project and barely taught us anything.

[hypervalent_iodine]

Perhaps you need to speak to your teacher then, as it doesn't make much sense to me. As written, it looks like you are just multiplying the amount of the substance you have the least of, while keeping the other one the same as in the previous question. This seems like a pointless question to me, but you should figure out why yourself rather than me give the game away.

 

Limiting reagents an extension of what you will have learnt from doing your previous question. Simply, you are looking at a case where you have more of at least one reagent than you need for the other to fully react. In the combustion question for example, you have figured out that for the reaction to go to completion, you need a certain amount of oxygen (which you calculated). Based on the stoicheometry ratios / coefficients, you can then relate this to work out how much product you'll get. In a made up example, let's say you have one mole of methane, and two of oxygen. This gives you one mole of CO2 and two moles of water, based on your reaction. If you had more oxygen but the same amount of methane, do you think you would have more product, less, or the same amount?

[Vultux]

Perhaps you need to speak to your teacher then, as it doesn't make much sense to me. As written, it looks like you are just multiplying the amount of the substance you have the least of, while keeping the other one the same as in the previous question. This seems like a pointless question to me, but you should figure out why yourself rather than me give the game away.

 

Limiting reagents an extension of what you will have learnt from doing your previous question. Simply, you are looking at a case where you have more of at least one reagent than you need for the other to fully react. In the combustion question for example, you have figured out that for the reaction to go to completion, you need a certain amount of oxygen (which you calculated). Based on the stoicheometry ratios / coefficients, you can then relate this to work out how much product you'll get. In a made up example, let's say you have one mole of methane, and two of oxygen. This gives you one mole of CO2 and two moles of water, based on your reaction. If you had more oxygen but the same amount of methane, do you think you would have more product, less, or the same amount?

Would it be more?

[hypervalent_iodine]

Would it be more?

 

 

No. Think about it a bit more. Where does the carbon from the CO2 in the product come from?

 

You should read up on what limiting reagents are, and how to deal with them in these sorts of calculations.

[Vultux]

 

 

No. Think about it a bit more. Where does the carbon from the CO2 in the product come from?

 

You should read up on what limiting reagents are, and how to deal with them in these sorts of calculations.

It comes from the methane gas. It says I need to convert the products and reactants into moles but how would I?

[hypervalent_iodine]

It comes from the methane gas. It says I need to convert the products and reactants into moles but how would I?

 

 

To your first comment: yes. So if you have the same amount of methane gas, even if there's more oxygen, how would you get more CO2? There isn't any extra carbon there.

 

As for your second comment...I'm a little confused as to how you answered the first question if you don't know how to convert between mass and moles.

[Vultux]

 

 

To your first comment: yes. So if you have the same amount of methane gas, even if there's more oxygen, how would you get more CO2? There isn't any extra carbon there.

 

As for your second comment...I'm a little confused as to how you answered the first question if you don't know how to convert between mass and moles.

 

So I would multiply the smallest reactant, CH4 by 4?

[hypervalent_iodine]

 

So I would multiply the smallest reactant, CH4 by 4?

 

 

Is that what the question asks you to do?