Charcoal is primarily carbon. Determine the mass of CO2 produced by burning enough carbon (in the form of charcoal) to produce 5.00 * 102 kJ of heat. C(s) + O2( g)¡CO2( g) ΔH °rxn = -393.5 kJ

Video transcript

All right. Hi, everyone. So this question says that charcoal is primarily carbon, determine the mass of carbon dioxide produced by burning enough carbon in the form of charcoal to produce 5.00 multiplied by 10 to the second kilojoules of heat. Now, here we have the chemical equation for the combustion of carbon and four different answer choices labeled A through D proposing different values for the mass of carbon dioxide in grams. Now, in this case, next to the chemical equation, we're given Delta H standard for this combustion reaction which equals negative 393.5 kg joules. Now because Delta H is negative recall, this means that heat has been produced as a result of this reaction, right? Is an exothermic process. Now, because we are given the amount of heat produced during this process, we can use this information to calculate the mass of carbon dioxide by treating it as a conversion factor. Notice how in the chemical equation provided one mole of carbon dioxide is produced on the on the product side. Of course, this means that for every one mole of carbon dioxide produced 393.5 kilojoules of heat are released. So we're going to use this correlation to find the mass of carbon dioxide. But before we do that recall also that the molar mass of carbon dioxide is equal to 44.01 g per mole. So lets go ahead and get started. No, in this case, we're going to start with the information that we were given, which was the amount of heat that we are intending to produce. Right. So my first value that I'm writing down is 5.00 multiplied by 10 to the second kilojoules. So this is the amount of heat that is needed. This is the amount of heat that we are intending to produce. So we're going to use delta H in this case to convert the heat needed into moles of carbon dioxide, which we can then convert into the mass of carbon dioxide. Now, to do that, we're going to treat this correlation as a conversion factor. So I'm going to treat it as a fraction with a numerator and a denominator. Now recall that the aim should always be to cancel out your starting unit. So if my starting units are kilojoules, then kilojoules should be in the denominator of my conversion factor. And the reason for this is to ensure that kilo jewels cancel out which they do. So by doing this, our answer is going to be expressed in moles of carbon dioxide. So now we can go from moles of carbon dioxide to grams of carbon dioxide. And we do that using the molar mass. So to do that, I need one more conversion factor in which moles of carbon dioxide should go in the denominator to make sure that those units cancel out, which means that the mass, the molar mass of carbon dioxide should go in the numerator. So after doing this, after setting up my second conversion factor, we can see that our answer is going to be expressed in grams of carbon dioxide, which is what we're looking for in this case. So to evaluate this expression, I'm going to go ahead and multiply together my numerators and divide by my denominators in my conversion factors. So after doing so and rounding to three significant figures, my final answer comes out to 55.9 g of carbon dioxide and this corresponds to option B in the multiple choice. So there you have it. And with that being said, thank you so very much for watching. And I hope you found this helpful.