# Chemistry

posted by
**Jessie T**
.

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?