Calculate the number of carbon atoms in 9g of carbon.

Answer 1

First determine what units you are given then find the units the problem asks you for

Given: mass (grams) Want to find: atoms

To go from mass to atoms we must first pass through moles (grams-->moles-->atoms):

1.) Convert grams to moles using atomic mass (the atomic mass of Carbon from the periodic table is 12.01 g/mol)

9 grams carbon x (1 mol carbon / 12.01 g carbon) = 0.7494 mol carbon

2.) Convert moles to atoms using Avogadro's number (1 mol substance = 6.022 x 10²³ particles)

0.7494 mol carbon x (6.022 x 10²³ carbon atoms / 1 mol carbon) = 4.5 x 10²³ carbon atoms

**You may need to adjust the math according to whether or not your teacher wants your answer using sig figs**

Hope this helps!