12.01 g of carbon atoms contains 6.02x10^23 carbon atoms. what is the mass in grams of 3.48x10^25 carbon atoms?

This is just showing you how to use a mole of anything (in this case carbon atoms).

Equation

Set up a proportion for solution.

Notice that the two units that are the same will eventually cancel out and you will be left with grams.

Solution

Multiply both sides by 3.48 * 10^25

Cancel out the powers and units that can be cancelled.

3.48*10 * 12.01 / 6.02 = x

Solve for x

x = 69.42 grams