Question

You need to make a 1L solution of 50mM TrisHCl pH 7.9, 150mM NaCl. You have stock solution of 1.5M Tris and 5M NaCl. How would you make this solution? Show Work

Answer 1

solution :-

We want to make the 1 L solution

we have initial molarities and final molarities

so using the formula M1V1 = M2V2 we can find the volume of the each solution needed to make the desired soluion

M1 of TrisHCl = 1.5 M * 1000 mM / 1 M = 1500mM TrisHCl

M1 of NaCl = 5 M NaCl * 1000 mM / 1 M = 5000 mM

now using these concnetrations lets calculate the volume of the stock solution needed.

Volume of the TrisHCl needed

V1= M2V2/M1

    = 50 mM * 1 L / 1500 mM

    = 0.0333 L TrisHCl

Volume of Stock NaCl needed

V1= M2*V2/M1

    = 150 mM *1 L/5000 mM

    = 0.03 L

So we need to use 0.0333 L of TrisHCl and 0.03 L NaCl stock solutions and dilute them with water to total volume of 1 L to get the desired concentration solution.