A carless chemistry student pours 200 grams of methanol, a flammable substance into the sink. Another careless chemistry student causes the bad situation to get even worse by dropping a lit match into the sink. The metanol burns completely with 300 grams of oxygen from the air.
A.) approximately what mass, in grams, is converted into energy? (I'm confused on how to justify this because the mass could be anything)
b.) What is the mass of the products in this chemical reaction?
c.) Approximtely what mass, in grams, is converted into different forms of matter?
I need clarification on what happens to the methanol and oxygen that reacts in this chemical reaction?
Frankly, I don't think the problem is written very well; however, I think you need to reread the problem. It says, "The methanol burns completely...." which tells me that all 200 g burned.
I don't know how to answer A. The gases will have some heat energy and some kinetic energy. Is this a freshman chemistry course or an advanced course? If an advanced course one could calculate the heat emitted from this reaction fairly easily.
B. 2CH3OH + 3O2 ==> 2CO2 + 4H2O
mols CH3OH = grams/molar mass = ?
mols O2 = grams/molar mass = ?
Using the coefficients in the balanced equation, convert mols CH3OH to mols CO2 and mols H2O.
Do the same for mols O2 to mols CO2 and mols H2O. You will find that mols CO2 and mols H2O are the same for each conversion which means that the exact amount of CH3OH is burned with the exact amount of oxygen which means this is not a limiting reagent problem.
Convert mols CO2 to grams. g = mols x molar mass = ?
Convert mols H2O to grams. g = mols x molar mass = ?
C. Why approximate? Total mass of products = g CO2 + g H2O
2CH3OH + 3O2 ==> 2CO2 + 4H2O
mols methanol = grams/molar mass = ?
mols O2 = grams/molar mass = ?
No this is freshman chemistry so that's why I asked such a question. Thanks for breaking it down. Although, what are the answers to them? kinda confused.
In this chemical reaction, methanol (CH₃OH) and oxygen (O₂) react to form carbon dioxide (CO₂) and water (H₂O). Let's break down each question and explain the reasoning behind them:
A.) To determine the approximate mass converted into energy, we need to recognize that a chemical reaction involves the rearrangement of atoms, but does not create or destroy them. The Law of Conservation of Mass states that the total mass before the reaction is equal to the total mass after the reaction.
In this case, the methanol and oxygen combine to form carbon dioxide and water, meaning none of the reactant's atoms are converted into energy. However, during the combustion reaction, energy is released in the form of heat and light. This energy is derived from the potential energy stored in the chemical bonds of the initial reactants.
While the reaction does generate energy, it doesn't involve the conversion of mass into energy. Therefore, the mass converted into energy is zero grams.
B.) The question asks for the mass of the products in this chemical reaction. From the reaction equation, we know that one mole of methanol reacts with one mole of oxygen to produce one mole of carbon dioxide and two moles of water.
The molecular weight of methanol (CH₃OH) is approximately 32 grams per mole, oxygen (O₂) is approximately 32 grams per mole, carbon dioxide (CO₂) is approximately 44 grams per mole, and water (H₂O) is approximately 18 grams per mole.
Given that 200 grams of methanol and 300 grams of oxygen react, we can calculate the theoretical yield of the products. By comparing the stoichiometric ratios, we find that the limiting reactant is methanol, as it's present in the smallest quantity, according to the balanced equation:
CH₃OH + O₂ -> CO₂ + H₂O
Based on this, 1 mole of methanol reacts with 1 mole of oxygen, producing 1 mole of carbon dioxide and 2 moles of water. Thus, the mass of products formed will be:
Mass of carbon dioxide = 1 mole * 44 grams/mole = 44 grams
Mass of water = 2 moles * 18 grams/mole = 36 grams
So, the mass of the products in this chemical reaction is approximately 44 grams of carbon dioxide and 36 grams of water.
C.) The mass converted into different forms of matter refers to the change in mass from the reactants to the products. Using the mass conservation principle, we can determine this by considering the difference in total mass between the reactants and products.
The initial mass in the reaction is 200 grams of methanol and 300 grams of oxygen, totaling 500 grams. The mass of the products, as calculated in part B, is 44 grams of carbon dioxide and 36 grams of water, totaling 80 grams.
Therefore, the approximate mass converted into different forms of matter is the difference between the initial mass and the final mass:
Mass converted = Initial mass - Final mass
Mass converted = 500 grams - 80 grams
Mass converted = 420 grams.
Hence, approximately 420 grams of matter are converted into different forms during this chemical reaction.