If 20 grams of NaF are used to make a 3.0 Liter solution. What is the concentration (Molarity) of the solution?
7M
0.23 M
0.16 M
62 M

0.16 M

Explanation:

molarity is a way to measure the concentration of solutions, the equation is the amount of solute in mol / liter of solution:

mol (solute) / L (solution)

the first thing you want to do is convert grams to moles:

20g NaF • 1 mol

———— = 0.47632464 mol

41.98817 g (molar mass of NaF)

then you just want to follow with the rest of the equation:

0.47632464 mol NaF / 3.0 L = 0.15877488 or 0.16 M (sigfigs)

hope this helps :)