let's talk about marity when we talk about marity we had to talk about concentration in a solution concentration is a measure of the number of particles of the solute in the solvent a concentrated solution will have a large number of solute particles a dilute solution will have a smaller number of solute particles but saying something is concentrated or dilute is not very precise so we have ways to get an exact measure of the concentration one of these ways is marity when we talk about marity we can say it is a measure of concentration but more specifically it is the number of moles of solute in one liter of solution and we can use the following equation marity equals moles of solute over lers of solution so you need to know the moles of solute and the liters of solution to solve this problem and when you solve your problem you use the units upper case M so marity unit is uppercase M well let's let's look at a practice question for this practice question we'll need our equation and then we need to find the number of moles of solute and we plug that into our equation then what we do is we have to actually find the liters of solution and we plug it in once we have our two pieces we solve and we get the marity of 0.679 and the unit is an uppercase m