If a 45.3-g sample of potassium nitrate is dissolved in enough water to make 225 mL of solution, what will be the molarity?
moles KNO3 = 45.3 g /101.1 g/mol=0.448
M = 0.448/ 0.225 L=1.99
the 101.1 is the molar mass of the KNO3, this was used to convert the grams into mols
Oh, potassium nitrate, the salt of choice for all aspiring chemists to dissolve! Now, to find the molarity, we need to divide the number of moles by the volume in liters. So first, let's convert that 45.3 grams to moles.
But before we do that, let's have a little joke to lighten the mood.
Why did the chemist open a bakery?
Because he kneaded a fresh molar solution!
Okay, now back to the question. The molar mass of potassium nitrate is 101.1 g/mol. So when we divide 45.3 grams by 101.1 g/mol, we find that we have 0.448 moles of potassium nitrate.
Next, we need to convert 225 mL to liters. Remember, there are 1000 mL in a liter, so 225 mL is 0.225 liters.
Now, we can divide the moles by the volume to find the molarity. That gives us a molarity of approximately 1.99 M.
So, the molarity of the potassium nitrate solution is around 1.99 M. Just make sure to dilute it with some laughter to reach optimal enjoyment!
To find the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters). Here's how you can calculate the molarity for the given problem:
Step 1: Convert the mass of potassium nitrate to moles.
To do this, you need to use the molar mass of potassium nitrate (KNO3), which is the sum of the atomic masses of its constituent elements (potassium, nitrogen, and oxygen). The molar mass of KNO3 is approximately 101.11 grams/mole.
Mass (g) = 45.3 g
Molar Mass (KNO3) = 101.11 g/mol
Number of moles = Mass (g) / Molar Mass (g/mol)
Number of moles = 45.3 g / 101.11 g/mol
Step 2: Convert the volume of the solution to liters.
The given volume is 225 mL. Since the molarity is expressed in liters, you need to convert milliliters to liters.
Volume (mL) = 225 mL
Volume (L) = 225 mL / 1000 mL/L
Step 3: Calculate the molarity.
Now that you have the number of moles of KNO3 and the volume of the solution in liters, you can calculate the molarity (M) using the formula:
Molarity (M) = Moles of solute (mol) / Volume of solution (L)
Using the values from steps 1 and 2:
Molarity (M) = Number of moles / Volume (L)
Finally, plug in the values:
Molarity (M) = (45.3 g / 101.11 g/mol) / (225 mL / 1000 mL/L)
Simplifying the expression:
Molarity (M) = (45.3 g / 101.11 g/mol) / (0.225 L)
Now, you can calculate the value to find the molarity.