Question

Calculate the gram amount of imidazole and volume of 10X PBS and water to use to make 10mL of a solution that is 1X PBS and 500mM imidazole

Calculate the gram amount of imidazole and volume of 10X PBS and water to use to make 10mL of a solution that is 1X PBS and 25mM imidazole.

Answer 1

Ans. Part 1:

# Required moles of imidazole = Molarity x Volume of solution in liters

                                                            = 0.500 M x 0.010 L

                                                            = 0.005 mol

Required mass of imidazole = Required moles x Molar mass

                                                = 0.005 mol x (68.077 g/ mol)

                                                = 0.1159 g

# Using           C1V1 (10X PBS) = C2V2 (1 X PBS)

            Or, (10X x V1) = (1X x 10 mL)

Or, V1 = (1X x 10 mL) / 10X = 1.0 mL

Therefore, required volume of 10X PBS solution = 1.0 mL

# Required volume of water = Total volume – Volume of 10X PBS taken

                                                = 10.0 mL – 1.0 mL

                                                = 9.0 mL

Note: It’s assume that addition of imidazole does not affect the volume of solution.

Part 2:

# Required moles of imidazole = Molarity x Volume of solution in liters

                                                            = 0.025 M x 0.010 L

                                                            = 0.00025 mol

Required mass of imidazole = Required moles x Molar mass

                                                = 0.00025 mol x (68.077 g/ mol)

                                                = 0.0170 g

# Using           C1V1 (10X PBS) = C2V2 (1 X PBS)

            Or, (10X x V1) = (1X x 10 mL)

Or, V1 = (1X x 10 mL) / 10X = 1.0 mL

Therefore, required volume of 10X PBS solution = 1.0 mL

# Required volume of water = Total volume – Volume of 10X PBS taken

                                                = 10.0 mL – 1.0 mL

                                                = 9.0 mL

Note: It’s assume that addition of imidazole does not affect the volume of solution.