What is the % mass of 12 M hydrochloric acid. Density of 12 M hydrochloric acid solution is 1.18 g/mL and the density of water is 1.00 g/mL

% w/w = (grams HCl/100 g soln)*100

12M is 12 mols/L soln
12 mols = 12*36.5 g/mol = about 438 g HCl
mass 1000 mL = 1180 grams (1.18 x 1000)
(438/1180)*100 = ? w/w

To find the mass percentage of a solution, you need to know the mass of the solute (hydrochloric acid) and the total mass of the solution.

In this case, the given concentration of hydrochloric acid is 12 M, which means you have 12 moles of hydrochloric acid per liter of solution. However, the density of the solution is given in grams per milliliter, so we need to convert the units.

To convert from mL to L, divide the volume by 1000:

1.18 g/mL ÷ 1000 = 0.00118 g/mL

Now we can calculate the mass of the solution. Since the density of water is 1.00 g/mL, the mass of 1 mL of the solution is equal to 1.00 g/mL. Multiply this by the total volume of the solution (1 mL) to get the total mass:

1.00 g/mL × 1 mL = 1.00 g

Next, we need to find the mass of the solute (hydrochloric acid). To do this, we can multiply the molarity (12 M) by the molar mass of hydrochloric acid. The molar mass of hydrochloric acid is the sum of the atomic masses of hydrogen (H) and chlorine (Cl):

H = 1.008 g/mol
Cl = 35.453 g/mol

So, the molar mass of hydrochloric acid is:

1.008 g/mol + 35.453 g/mol = 36.461 g/mol

To find the mass of the solute, multiply the molarity by the molar mass:

12 M × 36.461 g/mol = 437.532 g

Finally, we can calculate the mass percentage by dividing the mass of the solute by the total mass of the solution and multiplying by 100:

(mass of solute ÷ total mass of solution) × 100 = mass percentage

(437.532 g ÷ 1.00 g) × 100 ≈ 43753.2%

Therefore, the % mass of a 12 M hydrochloric acid solution is approximately 43753.2%.