Question

During the rGFP purification experiment, the instructor will have to make breaking buffer for the students to use. This buffer contains 150mM NaCl. Given a bottle of crystalline NaCl (M.W. = 40g/mole), describe how you would make 500ml of 150mM NaCl

Answer 1

Explanation:

1mM of solution means millimolar, that is 1 millimole of solute is contained in 1 liter of solvent.

Converting mM to M,

150mM to M = 150*1 x 10^-3

= 0.15M

Number of moles = molar concentration * volume

= 0.15*0.5

= 0.075 moles.

Molar mass of NaCl = 23 + 35.5

= 58.5 g/mol

Mass of NaCl = molar mass * number of moles

= 58.5*0.075

= 4.3875g

Description:

• 4.3875 g of NaCl is measured on a measuring scale and poured in a conical flask.

• 1 liter of solvent is measured with a measuring cylinder and poured into the conical flask and mixed.