Final answer:
The mass of 1.2x10^25 molecules of CO is calculated by finding the number of moles and then using the molar mass to find the mass, which is approximately 558.0313 grams.
Step-by-step explanation:
The student asked about the mass of 1.2x10^25 molecules of CO (carbon monoxide, not carbon dioxide as some provided information might suggest). To solve this, we need to use the concept of molar mass and Avogadro's number. First, we have to find out how many moles of CO 1.2x10^25 molecules represent. Since one mole contains 6.022x10^23 entities, divide the number of CO molecules by Avogadro's number:
Number of moles of CO = 1.2x10^25 molecules / 6.022x10^23 molecules/mole = 19.93 moles
Next, we need the molar mass of carbon monoxide, which is the sum of the atomic masses of carbon (12.01 amu) and oxygen (16.00 amu), making it approximately 28.01 g/mole. Now multiply the number of moles by the molar mass to find the mass:
Mass of CO = 19.93 moles * 28.01 g/mole = 558.0313 grams
Therefore, the mass of 1.2x10^25 molecules of CO is approximately 558.0313 grams.