Methane, CH4, burns in oxygen. (a) What are the products of the reaction? (b) In Write the balan

Methane, CH4, burns in oxygen. (a) What are the products of...

Key Concepts

Conservation of Mass

The conservation of mass principle states that in a closed system, mass is neither created nor destroyed during a chemical reaction. This principle underpins the need for balanced chemical equations and ensures that the total mass of reactants equals the total mass of products in any chemical process.

Mole Concept

The mole concept is a fundamental chemical concept that relates the mass of a substance to the number of particles it contains, using Avogadro’s number as a bridge between microscopic particles and measurable quantities. It is central to stoichiometric calculations, allowing chemists to convert between mass and number of molecules or atoms.

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships of reactants and products in chemical reactions. It involves the calculation of moles, mass, and volumes, using balanced equations to determine the exact amounts of substances consumed and produced in a reaction.

Balancing Chemical Equations

Balancing chemical equations is the process of ensuring that the number of atoms of each element is the same on both sides of the reaction. This practice adheres to the law of conservation of mass and is essential for accurately representing chemical reactions. It provides the quantitative relationships among reactants and products in any chemical equation.

Combustion Reactions

Combustion reactions involve a substance reacting with oxygen to produce heat and often light. In these reactions, the fuel is oxidized, typically producing carbon dioxide and water when carbon-based compounds are completely burned. The concept is fundamental in understanding energy release in chemical processes and is widely applicable in energy production and engine design.

Transcript

00:01 Hello friends, in this video we will try solving some questions related to combustion of methane.

00:09 So the first question is we have to write a balanced chemical equation for combustion of methane.

00:30 Okay, so when anything burns in presence of oxygen, it is called as combustion.

00:35 Right.

00:36 So in this question, we have to write an equation for a balanced chemical equation for combustion of methane.

00:43 So when we burn methane, so methane is ch4, right? so when we burn methane in presence of oxygen, it gives out carbon dioxide and water.

00:58 So this is methane, then it goes combustion.

01:03 So basically it combines or burns in presence of oxygen and it produces carbon dioxide and water.

01:14 Okay, so our equation is ready.

01:16 Now we need to balance it okay so let's first write what are the total number of atoms of each element on both the sides right so next part is balancing the equation so we write the reactants side the product side so we have carbon hydrogen oxygen these are the only three elements involved here right so similarly we have c h o okay so i mean you can take as a rule generally we should try to balance the metal atom first then the non -metal atom and then oxygen and then hydrogen atom okay so let's first count the number of carbon atoms on each side so on the left hand side we have only one carbon atom on the right hand side on product side we have only one carbon atom.

02:47 Similarly hydrogen atoms are four on the left hand side and it's only two on the right hand side.

02:55 Then oxygen atoms are two on the reactant side and three on the product side, right? okay, so let's so so so since there is no metal we go to the non -metal which is carbon so carbon is already balanced here.

03:25 So let's go to now oxygen.

03:27 So oxygen here is two and here it is three right so so two and three the common factor is six so let's put a three here and see in case it will help in balancing so three to just six so now it becomes six here and then let's try to put a two here so this way what will happen is if you put a two here so this way what will happen is if you put a 3 here what will happen hello friends in this video we will discuss some questions on combustion of methane okay so what is combustion first so when anything burns in presence of oxygen it is called as combustion and in this question we are specifically concerned about methane which is ch4 right so let's try to solve our first question so basically we have to write a balanced chemical equation for combustion of methane okay so so as i already mentioned combustion is anything burning in presence of oxygen so when methane burns in presence of oxygen it produces carbon dioxide and water molecule is produced right so this is the equation now we need to balance it right so let's label the compounds first so this is methane we have oxygen this is carbon dioxide and this is water right okay our next question is we have to balance this equation right so let's balance it so the b part is balancing the equation so ch4 plus o2 gives co2 plus h2 okay so first let's make a note of the different atoms on the reactant and the product side.

06:33 So we have carbon oxygen and hydrogen.

06:38 Carbon, oxygen and hydrogen.

06:41 So we always try to balance the metal atom first, then the non -metal atom, then oxygen and then hydrogen atoms.

06:50 So here we don't have any metal, so we go metal atoms, so we don't go to the carbon atom.

06:55 So on the left hand side you can see there is only one carbon atom on the product side also there is only one carbon atom on the reactant side you have two oxygen atoms on the product side you have three oxygen atoms on the reactant side you have four hydrogen atoms and on the product side you have two hydrogen atoms right okay so let's try balancing it so carbon is one on each side so that's already balanced then let's go to oxygen so oxygen is 2 here and then it is 3 here okay so suppose okay let's okay let's put a 2 here and see what happens and before that we can see that there is hydrogen is 4 here and then 2 here so see oxygen and hydrogen they are present together in water molecule right so let's do one thing in case we put a 2 here what happens the number of oxygen atoms becomes 4 right so now it becomes 4 oxygen atoms on the product side and then for making it 4 we have to just put a 2 here right so now it is balanced now let's check what happens to the hydrogen atoms so the hydrogen atoms become 4 as well right now our equation is balanced.

08:36 So methane combines with two molecules of oxygen giving a molecule of carbon dioxide and two molecules of water.

08:46 Right.

08:47 Okay so let's go to the next question now.

08:52 Okay so next question is a stoichiometric calculation question.

08:59 So it says what is the mass of oxygen in grams required for complete combustion of 25 .5 grams of methane.

09:43 Okay, so the question is how much oxygen in grams is required for complete combustion of 25 .5 gram of methane.

09:52 Right.

09:53 So, so let's try to do this question.

09:58 So from the balanced chemical equation, so from the balance chemical equation, we know that ch4 plus 2o2 gives co2 plus 2h2 plus 2h2 right so basically what is the molar mass of methane so how do we calculate it? we go to the periodic table check the atomic mass for carbon add up two atomic mass of four atoms of hydrogen.

10:50 So that comes out to be 12 plus 4.

10:53 4 into 1 is 4 so 16 grams per mole similarly for oxygen the oxygen gas oxygen molecule it will be 16 into 2 32 right so the molar mass is 32 grams per mole then similarly for carbon dioxide it is 44 grams per mole right and similarly for water it is 18 grams per mole so from the equation we can come to know that 16 grams of methane reacts with 32 into 2 which is 64 grams of oxygen giving 44 grams of carbon dioxide and 2 into 18 grams of water.

11:51 Right.

12:01 So this is the basic calculation we need to keep in our mind so as to calculate the part c.

12:08 Right.

12:09 So we need to find how much oxygen is required for complete combustion of 25 .5 grams of methane.

12:18 Right.

12:19 So we have calculated just now that 16 grams of methane reacts with 64 grams of oxygen.

12:30 Giving out 44 grams of carbon dioxide and 36 grams of water.

12:44 We just change it to o2 instead of oxygen, so that's fine...