You have a solution of 12.0 M HCl. You need 36.5 g of hydrochloric acid for a reaction in your chemistry lab. How many mL of solution must you use?

How many mols do you need? That's mols = grams/molar mass. You know molar mass and grams, solve for mols.

Then M HCl = mols HCl/L HCl. You know mols and M, solve for L and convert to mL.

To find the volume of 12.0 M HCl solution needed to obtain 36.5 g of hydrochloric acid, we first need to convert the mass of HCl to moles.

We can use the molar mass of hydrochloric acid (HCl) to convert grams to moles. The molar mass of HCl is 36.5 g/mol (as indicated in the question).

Next, we can use the balanced equation or molar ratio to determine the moles of HCl present in the solution. In this case, we assume that 1 mole of hydrochloric acid (HCl) corresponds to 1 mole of HCl in solution.

Finally, we can use the definition of molarity to calculate the volume of the solution. The formula for molarity (M) is:

M = moles of solute / volume of solution (in liters)

Rearranging the formula, we get:

volume of solution (in liters) = moles of solute / M

Let's calculate the volume of the solution needed:

Step 1: Convert grams to moles
moles of HCl = 36.5 g / 36.5 g/mol = 1 mol

Step 2: Calculate the volume of the solution
volume of solution (in liters) = 1 mol / 12.0 mol/L = 0.0833 L

To convert liters to milliliters, we multiply by 1000:
volume of solution (in mL) = 0.0833 L × 1000 mL/L = 83.3 mL

Therefore, you need to use 83.3 mL of the 12.0 M HCl solution in your reaction.