In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?

54

i know its not 18 i just checked and it was wrong so that marks that answer out.

well,

12g C + 32g O2 → 44g CO2

??

If all 18g of C were used, there would be only 66g CO2.

Am I missing something here?

I don't think so. I answered the same way for Mariah about a week ago. The problem may be a faulty one OR she is not posting the numbers correctly.

To determine the mass of oxygen needed in the reaction, we need to understand the law of conservation of mass. According to this law, the total mass of the reactants must be equal to the total mass of the products.

In this balanced chemical equation: C + O2 → CO2, we can see that one molecule of carbon reacts with one molecule of oxygen gas (O2) to produce one molecule of carbon dioxide (CO2).

Given that 18 g of carbon reacts to produce 72 g of carbon dioxide, we need to find the mass of oxygen that would be needed.

Let's start by calculating the molar mass of CO2 and C:

- The molar mass of CO2 is calculated by adding the atomic masses of one carbon atom (12.01 g/mol) and two oxygen atoms (16.00 g/mol each) together:
Molar mass of CO2 = (12.01 g/mol) + (16.00 g/mol x 2) = 44.01 g/mol

- The molar mass of C is simply the atomic mass of carbon:
Molar mass of C = 12.01 g/mol

Next, we can use the molar ratios from the balanced chemical equation to calculate the mass of oxygen required.

From the balanced equation: 1 molecule of C reacts with 1 molecule of O2 to produce 1 molecule of CO2.

Converting grams to moles:
- Moles of CO2 = Mass of CO2 / Molar mass of CO2 = 72 g / 44.01 g/mol ≈ 1.636 mol

Since the molar ratio of C to O2 is 1:1, the moles of oxygen needed would be the same as the moles of carbon dioxide produced.

Therefore, the mass of oxygen needed can be calculated as follows:
Mass of O2 = Moles of O2 x Molar mass of O2
= 1.636 mol x (molar mass of O2)

The molar mass of O2 is calculated by adding the atomic masses of two oxygen atoms (16.00 g/mol each):
Molar mass of O2 = 2 x 16.00 g/mol = 32.00 g/mol

Substituting the values:
Mass of O2 = 1.636 mol x 32.00 g/mol
≈ 52.352 g

Therefore, approximately 52.352 grams of oxygen would be needed in the reaction.

as did I.

it is 72.