Prepare 800 mL of 2M sodium chloride. How many grams of NaCl needs to be dissolve in a 800 mL distilled water?

93.6 g of NaCl.

Explanation:

We'll begin by converting 800 mL to litre (L). This can be obtained as follow:

1000 mL = 1 L

Therefore,

800 mL = 800 mL × 1 L / 1000 mL

800 mL = 0.8 L

Next, we shall determine the number of mole of NaCl in the solution. This can be obtained as follow:

Molarity = 2 M

Volume = 0.8 L

Mole of NaCl =?

Molarity = mole / Volume

2 = mole of NaCl / 0.8

Cross multiply

Mole of NaCl = 2 × 0.8

Mole of NaCl = 1.6 moles

Finally, we shall determine the mass of NaCl needed to prepare the solution. This can be obtained as follow:

Mole of NaCl = 1.6 moles

Molar mass of NaCl = 23 + 35.5

= 58.5 g/mol

Mass of NaCl =?

Mole = mass /Molar mass

1.6 = Mass of NaCl / 58.5

Cross multiply

Mass of NaCl = 1.6 × 58.5

Mass of NaCl = 93.6 g

Therefore, 93.6 g of NaCl is needed.