how much of each of the following substances would you add to water to prepare 1.20L of a .85M solution? (H2SO4 from "concentrated" (18M) sulfuric acid) ? I am stuck on how to work this one out. thanks
Two ways to do it.
18 M = 18 mols per liter.
You want 1.20 L x 0.85 M = 1.02 mols.
Then L x M = mols.
L x 18 = 1.02
L = ?? of H2SO4.
OR you can use the dilution formula.
L x M = L x M
L x 18 M = 1.20 L x 0.85 M
solve for Liters of H2SO4 @ 18 M.
To prepare a 1.20L solution of H2SO4 with a concentration of 0.85M using concentrated sulfuric acid (18M), you'll need to use the formula:
M1V1 = M2V2
Where:
M1 = concentration of concentrated sulfuric acid (18M)
V1 = volume of concentrated sulfuric acid needed (unknown)
M2 = desired concentration (0.85M)
V2 = final volume of the solution (1.20L)
Rearranging the formula, we get:
V1 = (M2 x V2) / M1
Substituting the values:
V1 = (0.85M x 1.20L) / 18M
V1 = (1.02 mol/L) / 18M
V1 = 0.0567L or 56.7mL
Therefore, you will need to add 56.7mL of concentrated sulfuric acid (18M) to water to prepare a 1.20L solution of H2SO4 with a concentration of 0.85M.
To determine how much concentrated sulfuric acid (18M) you need to prepare 1.20L of a 0.85M solution of H2SO4, you can follow these steps:
Step 1: Understand the problem
We want to prepare a solution with a final volume of 1.20L and a concentration of 0.85M H2SO4. We will be using concentrated sulfuric acid (18M) as the starting material. We need to calculate the amount of sulfuric acid needed and then dilute it to the desired concentration and volume.
Step 2: Use the Molarity formula
The molarity formula is: Molarity (M) = moles of solute / volume of solution (in liters).
Step 3: Calculate the moles of H2SO4
Since we know the desired molarity (0.85M) and the final volume of the solution (1.20L), we can use the formula from step 2 to calculate the moles of H2SO4.
moles of H2SO4 = Molarity × Volume (in liters)
moles of H2SO4 = 0.85 mol/L × 1.20 L
moles of H2SO4 = 1.02 moles
Step 4: Determine the volume of concentrated sulfuric acid needed
Since the concentration of the concentrated sulfuric acid is given as 18M, we can use the molarity formula (step 2) to determine the volume needed.
moles of concentrated sulfuric acid = Molarity × Volume (in liters)
1.02 moles = 18 mol/L × Volume (in liters)
Volume (in liters) = 1.02 moles / 18 mol/L
Volume (in liters) = 0.0567 L or 56.7 mL
Step 5: Calculate the volume of water needed
To prepare the desired solution, we need to dilute the calculated volume of concentrated sulfuric acid with water. Subtract the volume of concentrated sulfuric acid from the final volume of the solution to get the volume of water needed.
Volume of water = Final volume - Volume of concentrated sulfuric acid
Volume of water = 1.20 L - 0.0567 L
Volume of water = 1.1433 L or 1143.3 mL
In summary, to prepare 1.20L of a 0.85M H2SO4 solution using concentrated sulfuric acid (18M), you need to add 0.0567 L (56.7 mL) of the concentrated sulfuric acid and then dilute it with 1.1433 L (1143.3 mL) of water.