Solution hints. Often in this course, you will be given a concentrated stock solution and you will need to dilute it to the desired working concentration. Fortunately, this is easy! Just follow the equation: where C represent concentration and V represents volume. The subscript 1 refers to the starting solution (what you are given) and subscript 2 refers to what you need to make. For example, suppose you are given a 1 M sucrose solution (this is C_{1}), and you need to make a 50 mM (0.050 M) solution (this is C_{2}). You will first need to decide how much of the final solution you need (this is V_{2}). Suppose we want to make 10 milliliters (ml) of the working solution. The equation becomes: 1M * (V_{1}) = 0.050M * (10ml) Solving for V_{1}, we see that we need 0.5 ml of 1M sucrose to make 10 ml of a 50mM solution. The remainder of the solution (10 ml - 0.5 ml = 9.5 ml) should be deionized water. Important: Keep the units consistent. Notice that we put in a volume in ml, this means that the volume we calculate is also in ml. Notice also that we converted mM to M so that concentrations on both sides of the equation were in M. |