Did I do these right? Can someone let me know if I did them correctly? I had someone help me with the problems but know I want to make sure their the right answers?

1. Methane burns in oxygen according to the following equation:
CH4 + 2O2 ----> CO2 + 2H2O
What is the mass of CO2 produced when 3.4 grams O2 reacts according to the above reaction?
a. 4.7g
b. 4.9g
c. 2.3g
d. 9.4g
e. 0.74g
After doing the calculations I got 2.3g, is that correct? Did I do that right?

2. Determine the number of moles of MgO that form from the reaction of 4.4 moles of O2 in the following unbalanced reaction:
Mg + O2 ----> MgO
The balanced equation I get is:
2Mg + O2 ----> 2MgO
a. 1.1 moles
b. 4.4 moles
c. 17.6 moles
d. 2.2 moles
e. 8.8 moles
What I get after doing the calculations is d. 2.2 moles, is that correct? Did I do that right?

To check if your answers are correct, let's go through the calculations for each question and see if your answers match.

1. To find the mass of CO2 produced, you need to use the given mass of O2 and convert it to the mass of CO2 using the balanced equation.

Given:
Mass of O2 = 3.4 grams

Using the balanced equation, we can determine the stoichiometric ratio between O2 and CO2.

From the equation: CH4 + 2O2 -> CO2 + 2H2O
We can see that 2 moles of O2 produce 1 mole of CO2.

Now, let's calculate the moles of O2 first:
Moles of O2 = Mass of O2 / Molar mass of O2.

Molar mass of O2 = 32 g/mol (oxygen has a molar mass of 16 g/mol)

Moles of O2 = 3.4 g / 32 g/mol = 0.10625 mol (approximately)

Since the stoichiometric ratio between O2 and CO2 is 2:1, the number of moles of CO2 produced would be half that of O2.

Moles of CO2 = 0.10625 mol / 2 = 0.05313 mol (approximately)

Now, let's convert the moles of CO2 to mass:
Mass of CO2 = Moles of CO2 x Molar mass of CO2

Molar mass of CO2 = 44 g/mol (molar mass of carbon is 12 g/mol, and oxygen is 16 g/mol, so CO2 has a molar mass of 12 + (2 x 16) = 44 g/mol)

Mass of CO2 = 0.05313 mol x 44 g/mol = 2.33 g (approximately)

Therefore, the correct answer is not 2.3g, but rather option e. 0.74g.

2. To determine the number of moles of MgO formed, we need to use the given number of moles of O2 and the stoichiometry provided by the balanced equation.

Given:
Moles of O2 = 4.4 moles

Using the balanced equation: 2Mg + O2 -> 2MgO

From the equation, you can see that O2 and MgO have a stoichiometric ratio of 1:2.

Thus, if we have 4.4 moles of O2, we can calculate the moles of MgO formed:

Moles of MgO = (Moles of O2) x (2 moles of MgO / 1 mole of O2)
= 4.4 moles x (2 moles / 1 mole)
= 8.8 moles

Hence, the correct answer is e. 8.8 moles, not d. 2.2 moles.

In conclusion, your first answer is incorrect, and the correct answer for the first question is e. 0.74g. Your second answer is also incorrect, and the correct answer for the second question is e. 8.8 moles.