Molarity (M) is a unit of concentration in solutions. If a solution has a molarity of 2, we would identify it as 2M, and we say it is 2 molar. M means mol/L. So a 2M solution has a concentration of 2 mol/L.

The formula that allows you to answer this question is:

#M_1V_1=M_2V_2#

where #M_1# and #M_2# are the molarity of the solutions in mol/L, and #V_1# and #V_2# are the volume of the solutions in liters.

**Known**

#M_1="12.0 mol/L"#

#M_2="1.0 mol/L"#

#V_2="2.0 L"#

**Unknown** : #V_1#

**Solution**

Rearrange the equation to isolate #V_1#. Substitute the known values into the equation and solve.

#V_1=(M_2V_2)/M_1#

#V_1=(1.0color(red)cancel(color(black)("mol"))/color(red)cancel(color(black)("L"))xx2.0"L")/(12.0color(red)cancel(color(black)("mol"))/color(red)cancel(color(black)("L"))##=##"0.17 L"# rounded to two significant figures