Please help me with these! Thanks :)
Describe, in detail, how to make 5.5 liters of a 2.5 molar HCl solution from a 10.5 molar HCl stock solution.
How many grams of a stock solution that is 85.5 percent H2SO4 by mass would be needed to make 150 grams of a 45.0 percent by mass solution? Show all of the work needed to solve this problem.
you are diluting it 10.5/2.5 times, or 4.2 times. Which means, you want one part stock solution, and 3.2 parts water.
well, what is one part? 5.5/4.2=1.31 liters.
Take 1.31 liters of the stock solution (10.5M HCl), then add it to 3.2x1.31=4.19liters water.
always add acid to water.
label the solution.
To make a 5.5 liters of a 2.5 molar HCl solution from a 10.5 molar HCl stock solution, you can follow the steps below:
Step 1: Calculate the volume of the stock solution needed:
We can use the formula:
(Volume of stock solution) x (Molarity of stock solution) = (Volume of final solution) x (Molarity of final solution)
Here, we need to find the volume of stock solution required. Let's solve the equation:
(Volume of stock solution) x (10.5 M) = (5.5 L) x (2.5 M)
Volume of stock solution = (5.5 L x 2.5 M) / 10.5 M
= 1.31 L
So, you will need 1.31 liters of the 10.5 molar HCl stock solution.
Step 2: Calculate the volume of distilled water needed:
To prepare the final solution, we need to add distilled water to the stock solution. We can calculate this by subtracting the volume of the stock solution from the volume of the final solution:
Volume of distilled water = (Volume of final solution) - (Volume of stock solution)
= 5.5 L - 1.31 L
= 4.19 L
Therefore, you will need 4.19 liters of distilled water to make 5.5 liters of the 2.5 molar HCl solution.
Now, let's move on to the second question.
To find out how many grams of a stock solution that is 85.5 percent H2SO4 by mass would be needed to make 150 grams of a 45.0 percent by mass solution, you can follow the steps below:
Step 1: Determine the amount of H2SO4 needed in the final solution:
We can calculate this by multiplying the total mass of the final solution by the desired percentage of H2SO4:
Amount of H2SO4 needed = (Percentage of H2SO4 in the final solution) x (Mass of the final solution)
= 45.0% x 150 g
= 67.5 g
Step 2: Calculate the mass of the stock solution needed:
To find out how much of the 85.5% H2SO4 stock solution is necessary, we can set up the following equation:
(Mass of stock solution needed) x (Percentage of H2SO4 in the stock solution) = (Amount of H2SO4 needed)
(Mass of stock solution needed) x (85.5%) = 67.5 g
Solving for the mass of stock solution needed:
Mass of stock solution needed = 67.5 g / 85.5%
= 79.001 g
Therefore, you will need approximately 79.001 grams of the 85.5% H2SO4 stock solution to make 150 grams of a 45.0% by mass solution.