Calculate the grams or milliliters of solute needed to prepare the following solutions.
1.)75. g of a 7.0 % (m/m) KCl solution
2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution
3.) 270. mL of a 15.0 % (v/v) acetic acid solution
I really just need to know how to work the first problem then I can do the rest as long as all the rules apply
1.
7% m/m means 7 g solute in 100 g solution. So you want 75 g solution. How many g solute will that be. That's
7 x (75/100) = 5.25 g solute.
Place 5.25 g solute in 75-5.25 = 69.75 g H2O. I like to check these things to see that it really is 7%.
(5.25/75)*100 = 7.0% You may want to go through and adjust the significant figures. In practice you do it this way. Add 5.25 g solute to a tared beaker, add water until the balance reads 75.0 g and you have it.
Note in 2 that it is m/v so that means 8g/100 mL.
In 3 it is v/v which means mL solute/100 mL solution.
Sure, I can help with that! Let's tackle the first problem together.
1.) To find the grams of solute needed, we need to use the formula:
grams of solute = (percent concentration/100) * mass of solution
In this case, the percent concentration is 7.0% and the mass of solution is 75 g.
Substituting the values into the formula, we get:
grams of solute = (7.0/100) * 75
= 5.25 g
So, you would need 5.25 grams of KCl to prepare a 75 g solution of 7.0% KCl.
Now you can apply the same method to solve the other problems. Remember, for m/v (mass/volume) and v/v (volume/volume) solutions, the formulas remain the same, but the units change to milliliters.
I'm confident you can handle the rest of the problems with this guidance. Good luck!
To calculate the grams or milliliters of solute needed to prepare a solution, you can use the formula:
Amount of solute = (Percentage of solute / 100) x Total volume of the solution
Let's use this formula to solve the first problem:
1. 75 g of a 7.0% (m/m) KCl solution:
First, let's convert the percentage to decimal form:
7.0% = 7.0 / 100 = 0.07
Using the formula:
Amount of solute = (0.07) x Total volume of the solution
Amount of solute = (0.07) x Total volume
To solve for the total volume, we need to know the concentration of the solution.
If the concentration is not given, it's not possible to calculate the total volume or the amount of solute needed.
Please provide the concentration of the KCl solution so we can proceed with the calculation.
To calculate the grams or milliliters of solute needed to prepare a solution, you'll need to use the formula:
Amount of solute = (Percentage concentration/100) x Total volume of solution
Now let's work through the first problem, which involves preparing a 75g of a 7.0% (m/m) KCl solution.
Step 1: Understanding the given information
- The required solution concentration is 7.0% (m/m), which means 7.0 grams of KCl per 100 grams of solution.
- The desired total volume of the solution is not specified.
Step 2: Determine the total volume of the solution
Since the total volume of the solution is not provided, we'll assume a convenient value, such as 100 mL.
Step 3: Calculate the amount of solute
The percentage concentration is given as mass/mass (m/m), so we can set up a proportion:
(7.0 g KCl / 100 g solution) = (x g KCl / 75 g solution)
Cross-multiply and solve for x:
(x g KCl) = (7.0 g KCl / 100 g solution) x (75 g solution)
(x g KCl) = 5.25 g KCl
Therefore, you would need 5.25 grams of KCl to prepare a 75g of a 7.0% (m/m) KCl solution.
Now that you understand the process, you can apply the same approach to solve the remaining problems.