how many grams of a stock solution that is 85% H2SO4 by mass would be needed to make 150 grams of a 45.0 percent solution?
you want to dilute it 85/45= 1.889 times?
That means one part acid, .889 parts water.
So what is one part? 150/1.889=about 79grams acid, about 70.2g water.
To find out how many grams of the stock solution you would need, you can use the concept of the mass percentage.
First, let's break down the information given:
1. The stock solution is 85% H2SO4 by mass.
2. You need to make 150 grams of a 45.0% solution.
Now, follow these steps to calculate the grams of the stock solution needed:
Step 1: Determine the amount of H2SO4 in the desired solution:
The desired solution is 45.0% H2SO4, so the mass of H2SO4 in the solution can be calculated as:
(45.0 / 100) × 150 grams = 67.5 grams
Step 2: Determine the amount of H2SO4 in the stock solution:
Since the stock solution is 85% H2SO4, the mass of H2SO4 in the stock solution can be calculated as:
(85 / 100) × x grams, where x is the mass of the stock solution in grams.
Step 3: Set up the equation:
Equating the amount of H2SO4 in the desired solution and the stock solution:
67.5 grams = (85 / 100) × x grams
Step 4: Solve for x:
Divide both sides of the equation by (85 / 100) to isolate x:
x grams = (67.5 grams) / (85 / 100)
Step 5: Calculate x:
Now, calculate the value of x using a calculator:
x grams ≈ 67.5 grams * (100 / 85)
x grams ≈ 79.41 grams
So, approximately 79.41 grams of the stock solution that is 85% H2SO4 by mass would be needed to make 150 grams of a 45.0% solution.