You have a 5 M NaCl stock solution. (NaCl F. W. is 58.4) a) How much NaCl (in g) do you need to make 1 liter of the 5 M stock solution? b) How much stock solution will you need if you want to make 100 ml of 50 mM NaCl? c) What is the % concentration of a 50 mM solution of NaCl?

a) 292.0 g

b) 1 ml

c) 0.29 %

Explanation:

a) The amount of NaCl can be calculated as follows:

Where:

m: is the mass of NaCl =?

C: is the concentration of NaCl = 5M

V: is the volume = 1 L

M: is the molar mass of NaCl = 58.4 g/mol

Hence, you need to take 292.0 g of NaCl to make 1 L of 5 M stock solution.

b) We need to use the following equation to find the quantity of stock solution that is needed to make 100 ml of 50 mM of NaCl:

Where:

C₁: is the initial concentration = 5 M

V₁: is the volume of the initial concentration =?          

C₂: is the concentration of the solution to prepare = 50 mM

V₂: is the volume of the solution to prepare = 100 ml

Therefore, you need 1 ml of the stock solution to make 100 ml of 50 mM NaCl.

c) The % concentration of a 50 mM solution of NaCl is:

Hence, the % concentration is 0.29 % (w/v).

I hope it helps you!

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both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .