<p>Hi, in my class, we are currently doing Stoichiometry. The teacher explained it but I didn’t get any of it. Could someone show me how to do these problems?</p>
<li><p>How many kilograms of methane can be produced from 1000 kg of coal?</p></li>
<li><p>If a plant needs to make 30.0 g of glucose, C6H12O6, through the process of photosynthesis, how many grams of water are required?</p></li>
</ol>
<p>Thanks.</p>
<p>Use the equations you have and use gram-mole-mole-gram provided you know how to make gram to mole converstions, then mole to mole conversions using the ratio of the moles in the equation, finally convert back to grams. Get it? I would go further, but I'm lazy</p>
<p>Sorry, but I did not understand a thing you just said. :</p>
<p>Well, did those questions come with equations. If not, those BALANCED chemical equations must first be written. Do that for me, then we will continue from there.</p>
<p>I got the first one balanced, 2C+2H2O -> CH4+CO2.</p>
<p>Okay very good. Now, let's take a look. We have 1000 kg of coal.<br>
1. Convert this to grams.<br>
2. Now use your periodic table of the elements and convert the grams into moles by multiplying by the molar mass of carbon. Got it?
3. Now multiply your moles by the mole ratio of carbon to methane. So, multiply by 2/1. Get how I got that?
4. Now you have the moles of methane. Multiply by the molar mass of methane to get it into grams. Now use a conversion factor to get it to the kilograms the problem wants.</p>
<p>I won't solve it for you, but get me an answer and I will check it. I can also check the second one</p>
<p>And the second, 6CO2+6H2O -> C6H12O6 + 6O2.</p>
<p>Okay, good equation. Do you think you can use the same guidelines to solve this one? Only you don't need to convert with kilgrams since they give it in grams and want grams. If you need help, I'll show you this one too. I can check the answer. Also remember g-m-m-g because sometimes you may not need as much work. If they give in mole and want answer in moles, piece of cake. Get how there are several types of questions that can be asked, just use which parts of the g-m-m-g thing you need to get your answer in proper units.</p>
<p>Never mind, I'm too slow at explaining :( The answers above are correct though.</p>
<ol>
<li>1,000,000g</li>
<li>Umm 1,000,000g/24.02(Would I double it since there are 2 Carbon?)=41631mol</li>
<li>41631/2=20815.5</li>
<li>20815.5*16.05=334088.8g=334kg</li>
</ol>
<p>=x</p>
<p>zp, carbon and coal are the same. you mean methane and coal. put op, i got the answer if you want it checked.</p>
<p>NO, for step 2, do not double it. Leave that alone..the mole ratio takes care of it in step 3. Try that again.</p>
<ol>
<li>1,000,000g</li>
<li>Umm 1,000,000g/12.01=83263.9</li>
<li>83263.9/2=41631.9</li>
<li>41631.9*16.05=668191.9g=668kg</li>
</ol>
<p>Very good work! Try to get the 2nd one now. Just depending on how picky your teacher is, some teachers want to see it expressed in the appropriate amount of decimals spaces, but some don't care.</p>
<p>My teacher isn't really picky, luckily. :D
For the second one, I'm not sure where to start, this one confuses me more than the first.</p>
<p>Well, try the same thing. You are just working backwards..it's no harder. Start with the grams of glucose you have, get it to moles. You have a mole ratio. You can get it to grams of water needed from there.</p>
<p>Here goes...
1. 30g/180.18=.1665 mol
2. .1665<em>6=.999
3. .999</em>18.02=18.00198g</p>
<p>I hope that's right >_<</p>
<p>Bingo! You've got it! Any other concerns?</p>
<p>Do you see how all you need to remember is g-m-m-g?</p>
<p>THANK YOU! I think I got the hang of it now. :)</p>