Regarding previous post: I don't understand what I'm doing. My book says the answer is .50 M Ba(NO3)2 but I'm not getting that.
You didn't tell me your answer but I'll bet is is 1 M Ba(NO3)2. You're forgetting the dilution of each of the reagents by each other. You should have 1 mole Ba(NO3)2 left over and that in 2 L is 0.5 M. Is that what you're doing?
Dr Bob is right: you have 1 mole Ba(NO3)2 in two liters of solution, that is by definitiona, .5M
i made a mistake along the way but i cant find it to fix it. should i have done 4 mol/2 L instead of 2 mole/1 L
No.
2AgNO3 + BaCl2 ==> 2AgCl + Ba(NO3)2
2 x 1 = 2 moles AgNO3
2 x 1 = 2 moles BaCl2
AgNO3 is limiting; that is
2 moles AgNO3 will use 1 mole BaCl2.
At equilibrium,
All of the AgNO3 has been used.
BaCl2 = 2 moles initially - 1 mole reacted = 1 mole remaining.
1 mole/2L = 0.5 M.
If your book states that the answer to a problem is 0.50 M Ba(NO3)2, but you are getting a different result, it's important to go through the steps of the problem-solving process and review your calculations. Let's break down the problem and explain the steps to calculate the molarity.
To find the molarity (M) of a solution, you need to know the number of moles of the solute (in this case, Ba(NO3)2) dissolved in a certain volume of solvent (usually measured in liters). The formula for molarity is Moles of Solute / Liters of Solution.
1. Determine the number of moles of Ba(NO3)2: To do this, you'll need to know the mass of Ba(NO3)2 and the molar mass of the compound. The molar mass of Ba(NO3)2 can be calculated by adding the atomic masses of its constituent elements: Ba (Barium), N (Nitrogen), and O (Oxygen). Make sure to consider the subscripts as well.
2. Calculate the moles of Ba(NO3)2: Divide the given mass of Ba(NO3)2 by its molar mass to obtain moles.
3. Determine the volume of the solution: You'll need to know the volume of the solution in which Ba(NO3)2 is dissolved. This volume should be measured in liters.
4. Calculate the molarity: Divide the moles of Ba(NO3)2 by the volume of the solution in liters.
Now that we've gone through the general steps, let's work through an example.
Example:
Suppose you have 20 grams of Ba(NO3)2 dissolved in a total volume of 0.040 L solution. Calculate the molarity of the Ba(NO3)2 solution.
1. Determine the molar mass of Ba(NO3)2:
Ba: 1 * 137.33 g/mol = 137.33 g/mol
N: 2 * 14.01 g/mol = 28.02 g/mol
O: 6 * 16.00 g/mol = 96.00 g/mol
Molar mass of Ba(NO3)2: 137.33 + 28.02 + 96.00 = 261.35 g/mol
2. Calculate moles of Ba(NO3)2:
Moles = mass / molar mass
Moles = 20 g / 261.35 g/mol = 0.0764 mol
3. Determine the volume of the solution:
Given volume = 0.040 L
4. Calculate the molarity:
Molarity = moles / volume
Molarity = 0.0764 mol / 0.040 L = 1.91 M
Based on this calculation, the molarity of the Ba(NO3)2 solution is 1.91 M, which is different from the value mentioned in your book (0.50 M). Please double-check your calculations and variables to ensure accuracy.