Multiple choice
When methane is burned with oxygen, the products are carbon dioxide and water. If you produce 18 grams of water from 8 grams of methane and 32 grams of oxygen, how many grams of carbon dioxide were produced in the reaction?
a)40
b)22
c)58
D)18
Write the equation and balance it. This problem is all about recognizing the conservation of mass.
CH4 + 2O2 ==> CO2 + 2H2O
..8....32......x......18
..8 + 32 = x + 18. What's x?
22 grms of carbondioxide is produced in the reaction
How many grams of carbon tetrachloride can be produced from reacting 709.0 grams of chlorine with excess methane?
To solve this question, we need to use the concept of stoichiometry, which is the quantitative relationship between reactants and products in a chemical reaction.
First, let's write the balanced chemical equation for the combustion of methane:
CH₄ + 2O₂ → CO₂ + 2H₂O
From the equation, we can see that the molar ratio between methane (CH₄) and carbon dioxide (CO₂) is 1:1. This means that for every 1 mole of methane, we get 1 mole of carbon dioxide.
To find the number of moles of methane, we divide the given mass (8 grams) by the molar mass of methane. The molar mass of methane is calculated by adding up the atomic masses of each element: 12.01 g/mol for carbon (C) and 4.03 g/mol for hydrogen (H). So, the molar mass of methane is (12.01 g/mol * 1) + (4.03 g/mol * 4) = 16.05 g/mol.
Number of moles of methane = mass of methane / molar mass of methane
Number of moles of methane = 8 g / 16.05 g/mol ≈ 0.498 moles
Now, based on the stoichiometry of the balanced equation, we know that 1 mole of methane produces 1 mole of carbon dioxide. Therefore, the number of moles of carbon dioxide produced is also 0.498 moles.
To find the mass of carbon dioxide produced, we multiply the number of moles by the molar mass of carbon dioxide. The molar mass of carbon dioxide is calculated by adding up the atomic masses of carbon (12.01 g/mol) and two oxygen atoms (16.00 g/mol * 2). So, the molar mass of carbon dioxide is 12.01 g/mol + (16.00 g/mol * 2) = 44.01 g/mol.
Mass of carbon dioxide = number of moles of carbon dioxide * molar mass of carbon dioxide
Mass of carbon dioxide = 0.498 moles * 44.01 g/mol ≈ 21.88 grams
Therefore, approximately 21.88 grams of carbon dioxide were produced in the reaction.
None of the choices provided matches the calculated mass. However, the closest option is
b) 22 grams