The first task you are assigned in your summer laboratory job is to prepare a concentrated NaOH stock solution. The molecular weight of NaOH is 40. How many grams of solid NaOH will you need to weigh out to obtain a 500 mL solution that has a concentration of 10 M

200g of NaOH

Explanation:

The following data were obtained from the question:

Molar mass of NaOH = 40g/mol

Volume = 500mL

Molarity of NaOH = 10M

Next, we shall determine the number of mole of NaOH present in the solution. This is illustrated below:

Molarity of NaOH = 10M

Volume = 500mL = 500/1000 = 0.5L

Mole of NaOH =...?

Molarity = mole /Volume

10 = mole /0.5

Cross multiply

Mole = 10 x 0.5

Mole of NaOH = 5 moles

Finally, we can convert 5 moles of NaOH to grams. This is illustrated below:

Molar mass of NaOH = 40g/mol

Mole of NaOH = 5 moles

Mass of NaOH =...?

Mole = Mass /Molar Mass

5 = Mass /40

Cross multiply

Mass = 5 x 40

Mass of NaOH = 200g

Therefore, 200g of NaOH is needed to prepare the solution.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.