*.How many grams of KCl would you need to add to 2 liters of water to make a .50 M solution?
To calculate the number of grams of KCl needed to make a 0.50 M solution in 2 liters of water, you'll need to follow these steps:
Step 1: Find the molecular weight of KCl.
- The atomic weight of K (Potassium) is 39.10 g/mol.
- The atomic weight of Cl (Chlorine) is 35.45 g/mol.
- The molecular weight of KCl is therefore: 39.10 + 35.45 = 74.55 g/mol.
Step 2: Calculate the number of moles of KCl needed.
- To make a 0.50 M solution, you need 0.50 moles of KCl per liter of water.
- In 2 liters of water, you will need 0.50 moles/L x 2 L = 1.00 moles of KCl.
Step 3: Convert moles to grams.
- Multiply the number of moles needed by the molecular weight of KCl:
1.00 moles x 74.55 g/mol = 74.55 grams.
Therefore, you would need to add 74.55 grams of KCl to 2 liters of water to make a 0.50 M solution.
To determine the number of grams of KCl needed to make a 0.50 M solution, we need to follow a step-by-step process. Here's how to calculate it:
Step 1: Convert the volume from liters to milliliters (ml):
Since 1 liter is equal to 1000 milliliters, multiply 2 liters by 1000 to convert it to 2000 ml.
Step 2: Calculate the number of moles (mol) of KCl needed:
The molarity (M) is defined as the number of moles of solute per liter of solution. In this case, we want to make a 0.50 M solution.
Molarity (M) = moles of solute / liters of solution
Rearranging the equation to solve for moles of solute:
moles of solute = Molarity (M) * liters of solution
moles of solute = 0.50 mol/L * 2 L
moles of solute = 1.00 mol
So, we need 1.00 mole of KCl to make a 0.50 M solution.
Step 3: Determine the molar mass of KCl:
The molar mass of KCl can be found by adding the atomic masses of potassium (K) and chlorine (Cl).
Molar mass of KCl = atomic mass of K + atomic mass of Cl
Molar mass of KCl = 39.10 g/mol + 35.45 g/mol
Molar mass of KCl = 74.55 g/mol
Step 4: Calculate the grams of KCl needed:
Using the relationship between moles and grams:
grams of KCl = moles * molar mass
grams of KCl = 1.00 mol * 74.55 g/mol
grams of KCl = 74.55 grams
Therefore, you would need 74.55 grams of KCl to add to 2 liters of water to make a 0.50 M solution.
You want 2 L of 0.50 M. How many mols is that? That's mols = M x L = ?
Then mols = grams/molar mass. You know mols and molar mass, solve for grams.