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Chemical Reactions and Stoichiometry - Example 4

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity. Chemical reactions are usually characterized by a chemical change, and they yield one or more products after the reaction is complete. Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions. Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration. Typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms.

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So for our last problem will be looking at Thekla Bostian, pro bono with oxygen gas. Well, first, right the products of the reaction and then balanced the equation and then proceed to the next question. Where if we have 2 g of pro bono reacting with 0.5 g of oxygen cast, Um, we'll need to determine what the total number of option atoms are on the product side of the reaction. And so we know that this is a combustion reaction on DSO. We know that we produce carbon dioxide as one product as well as water for the second product and for the next part for balancing the equation will need Thio work with each atom one at a time and then figure out how to get an equal number of atoms of each element on the left and right side. So if we look at the number of carbons first, we can see that right now we have three carbons on the left side and one carbon on the right side. And so, for now we can put a coefficient of three in front of bot. Now, when we look at the number of hydrogen on the left side versus the right side. We see that we have eight hydrogen on the left side and two on the right side. And so for now we can write a coefficient of four in front of water. And when we look at the number of oxygen's on the left and right side, we see that we have three on the left, and we have a total of six plus four, which is 10 atoms of oxygen. And so, um, we can get ton by having 4.5 molecules of option on left side. And so we have nine plus one, Um, but when we write balance equations, we can't have half a molecule, and so we can multiply all the coefficients by two to get a new coefficient for all of the molecules. So when we do this mean 10, so let me just varies. He's very quickly. So if we right thief final coefficients for each molecule we have to. In front of personal, we have nine in front of oxygen gas, six in front of carbon dioxide and eight in front of water. And let's still check to make sure this is right So we have six carbons on the left side and six on the right side, so that looks good. We have 16 atoms of hydrogen and 16 on the right side, so that looks good. And finally, um, we have to plus 18 auction atoms, which is 20 on the left side. And we have 12 plus eight on the right side, and so we can see that we have 20 oxygen atoms on the last and right side, and so we can see that we have successfully balanced the equation. And so this answer is part a. The now for a party. We need to determine the number off auction Adams on the product side of the reaction. And so to do this, we first need to use, um, the masses that we're getting to determine the limiting reactant for the erection. And then from there, used the limiting reactant to find the number of moles of carbon dioxide and water because they both have oxygen atoms in them and then from there, determine the number of multiples off each product. And finally, the number of auction atoms that are from the products of the reaction and so first we can determine the learning Regent by deterring the moles of both reacting expressed. So starting with propranolol, which has a chemical formula of C three, age 80 we have three atoms of carbon, eight atoms of hydrogen as well as one oxygen atoms. And if we add this up, we get a Mueller Mass 60.9 grams Permal. And from here we can determine the moles using the masculine. So this problem were given that we have 2 g of criminal eso, we can divide the molar mass by the mass given, which will then give us 0.3328 moles. And in this particular case, it's important to normalize thes number of moles because for every two moles of criminal, it reacts with nine moles of oxygen gas. And so we need to divide this by the coefficient in front of corporal which is to and so our finals R 0.1664 And now we have the bowls for capital and now we need to do the same thing or oxygen gas. So for auction gas and simply has to auction atoms. And so the Mueller Mass is 32 grams Permal, and now we need to use the mask that were given, which is 0.5 g. And then we're going to divide this by the molar mass of oxygen, which will give us, um 0.0 156 three malls of 02 And like before, we need to divide this by the coefficient in front of the molecules based on the chemical equation. Thio kind of normalize the moles so we can compare them together. And so we divided by nine, which ends up giving us 1.736 times 14th months. So we can see that if we write this in scientific notation, this would be 1.664 times 10 to the negative, too. And so, if you compare these values now, we can see that oxygen is the limiting, reactant this equation. And so we need to use this to figure out the next part of the problem, which is to determine the total number of oxygen atoms on the product side of the reaction. And so now that we have normalized this weaken, simply multiply thieves by the coefficient, um, in front of each product to determine the number of moles for each one and then from there, determine the number of auction Adams. So if we work with carbon dioxide first, uh, that would mean that we can multiply six by the moles that we determined using document gas, and then multiply this by Allah God rose number, which is, and molecules one more. And in this case, since CO two has to auction Adams, we also need to multiply this by two. And so when we do out the math, we get a final answer of 1.255 times tend to the joint first. Oh, Adams. And now we can do the same thing, um, for water. And so here we have a coefficient of eight. So we'll be doing it multiplied by the number of moles of the limiting reactant before, which is which is oxygen gas. And then we'll multiply this by other god Rose number Thio get the units that we want. And in this case, there is only one, um, oxygen atoms in one molecule of water, and so we don't need to multiply this by anything else. And so our final answer will be mhm 0.364 times 10 to 20 0 atoms. And to calculate the total number of auction items on the product side, we just need Thio. Add our answer from this problem and this problem and what we're left with is a total number of 2.9 one times 10 to the 21st oxygen atoms. And this will be your final answer to this problem. And so from here, we can see that if we're given the masses of two reactions, we need to figure out which one is eliminate reactant. And then from there we can use this information to determine the number of moles of what we're interested in. And in this case, it is the number of moles off the products. And then we can use that, um, to determine the number of molecules or the number of atoms, depending on the problem using avocados number. And then from there, we should be able to answer these questions, um, about chemical reactions

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University of Central Florida

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