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Calculating the mass of gas produced when given a mass of a reactant?

When given an equation, such as combustion of an alkane. I know how to calculate the mass of a gas when the two masses of the reactants are given. E.g. to do with limiting and excess reactant, calculating which one is limiting and then using the ratios to calculate each ones no. of moles..

But I don't know how to calculate the mass of a reactant when only one mass of a reactant is given?
This is the question i'm stuck on:

Calculate the mass of this gas produced when 1 tonne of decane is burnt. C10H22 + 6.5O2 ---> 10CO2 + 11H20

Can anyone help me on this?
Original post by howeschloe
When given an equation, such as combustion of an alkane. I know how to calculate the mass of a gas when the two masses of the reactants are given. E.g. to do with limiting and excess reactant, calculating which one is limiting and then using the ratios to calculate each ones no. of moles..

But I don't know how to calculate the mass of a reactant when only one mass of a reactant is given?
This is the question i'm stuck on:

Calculate the mass of this gas produced when 1 tonne of decane is burnt. C10H22 + 6.5O2 ---> 10CO2 + 11H20

Can anyone help me on this?


So, burning 1 mole of decane produces 10 moles of CO2, right? You can get that from your equation.

Now, you have to work out how many moles of decane are in 1 tonne of decane (remember to convert to grams).

When you have this, multiply by 10 because 1 mol decane ==> 10 mol CO2.

Finally, multiply the number of moles of CO2 by it's RMM and you're done.

Hope this helps :smile:

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Reply 2
Thanks, you're a star!

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