1. How many grams are in 0.20 moles of N,?

Explanation:

To convert from moles to grams, we must use the molar mass.

1. Molar Mass

The molar mass of an element can be found on the Periodic Table. We are looking for nitrogen or N.

2. Convert from moles to grams

Use the molar mass as a ratio or fraction.

Multiply the given number of moles (0.20) by the fraction we just made.

When multiplied, the moles of nitrogen will cancel each other out.

The denominator of 1 can be ignored to create a simple multiplication problem.

3. Round

The original measurement of moles (0.20) gives 2 significant figures, the last 2 and 0.

Therefore, we must round our answer to 2 sig figs. This is the tenths place for this number of grams we found.

The 0 in the hundredth place tells us to leave the 8 in the tenth place.

There are about 2.8 grams of nitrogen in 0.20 moles of nitrogen.