How to calculate concentration of solution when it's diluted?

1 Answer
Feb 15, 2014

To calculate the concentration of a diluted solution, you use the formula #c_1V_1 = c_2V_2#

Example

Calculate the concentration of NaCl if enough water is added to 100 mL of a 0.250 mol/L sodium chloride solution to make 1.50 L of dilute solution.

Step 1: Make a table of the data.

#c_1# = 0.250 mol/L; #V_1# = 100 mL = 0.100 L
#c_2# = ?; #V_2# = 1.50 L

Step 2: Solve the formula for #c_2#.

#c_1V_1 = c_2V_2#

# c_2 = c_1 × V_1/V_2#

Step 3: Substitute the values and solve.

# c_2 = c_1 × V_1/V_2# = 0.250 mol/L × #(0.100 L)/(1.50 L)# = 0.0167 mol/L