CrCl3(s) + AgNO3 (aq)= AgCl(s) + Cr(NO3)3(aq)
A 0.750 g sample of impure CrCl3 was removed from a bottle that contained 1.75 g of impure sample. The removed sample was dissolved in water and required 42.5 mL of 0.215 M AgNO3 solution to react with the CrCl3 in the sample. What was the mass percent of CrCl3 in the sample?
CrCl3 + 3AgNO3 ==> 3AgCl + Cr(NO3)3
moles AgNO3 used = M x L = ?.
moles CrCl3 = 1/3 x moles AgNO3.
g CrCl3 = mols x molar mass
%CrCl3 = (grams CrCl3/mass sample)*100 = ??
For mass sample use 0.750 for percent CrCl3 in the "removed" sample; use 1.75 if you want the percent in the original sample. The way you have the worded the problem (you have two samples) I can't tell which percent you want.
To find the mass percent of CrCl3 in the sample, we need to calculate the amount of CrCl3 reacted with AgNO3 and then determine the mass of CrCl3 in the original sample.
Step 1: Calculate the moles of AgNO3 used:
We can use the volume and molarity of AgNO3 solution to calculate the moles of AgNO3 used.
Moles of AgNO3 = Volume (L) x Molarity (mol/L)
Given:
Volume of AgNO3 solution = 42.5 mL = 0.0425 L
Molarity of AgNO3 solution = 0.215 M
Moles of AgNO3 = 0.0425 L x 0.215 mol/L = 0.0091375 mol of AgNO3
Step 2: Determine the moles of CrCl3 reacted:
From the balanced chemical equation, we can see that the mole ratio between AgNO3 and CrCl3 is 1:1. Therefore, the moles of AgNO3 reacted are equal to the moles of CrCl3 reacted.
Moles of CrCl3 reacted = Moles of AgNO3 used = 0.0091375 mol
Step 3: Calculate the mass of CrCl3 used:
To find the mass of CrCl3 used, we need to multiply the moles of CrCl3 reacted by its molar mass.
Molar mass of CrCl3 = (1 mol Cr x atomic mass of Cr) + (3 mol Cl x atomic mass of Cl)
= (1 mol x 52.0 g/mol) + (3 mol x 35.45 g/mol)
= 52.0 g/mol + 106.35 g/mol
= 158.35 g/mol
Mass of CrCl3 used = Moles of CrCl3 reacted x Molar mass of CrCl3
= 0.0091375 mol x 158.35 g/mol
= 1.444 g
Step 4: Calculate the mass percent of CrCl3 in the sample:
Mass percent of CrCl3 = (Mass of CrCl3 used / Mass of the original sample) x 100%
= (1.444 g / 1.75 g) x 100%
= 82.54%
Therefore, the mass percent of CrCl3 in the sample is approximately 82.54%.
To find the mass percent of CrCl3 in the sample, we need to determine the amount of CrCl3 in the solution and then calculate the mass percent.
Let's break down the problem step by step:
Step 1: Calculate the amount of CrCl3 in the solution.
To do this, we need to find the moles of AgNO3 that reacted with CrCl3. From the balanced equation, we can see that the molar ratio between AgNO3 and CrCl3 is 1:1. Therefore, the moles of AgNO3 used will be equal to the moles of CrCl3 in the sample.
First, calculate the moles of AgNO3 used:
Moles of AgNO3 = volume (in L) x concentration (in mol/L)
Moles of AgNO3 = 42.5 mL x (1 L / 1000 mL) x 0.215 mol/L
Step 2: Calculate the mass of AgNO3 reacted with CrCl3.
To do this, we need to use the molar mass of AgNO3.
Molar mass of AgNO3 = atomic mass of Ag + atomic mass of N + (3 x atomic mass of O)
Molar mass of AgNO3 = (107.87 g/mol) + (14.01 g/mol) + (3 x 16.00 g/mol)
Now, calculate the mass of AgNO3:
Mass of AgNO3 = moles of AgNO3 x molar mass of AgNO3
Step 3: Calculate the moles of CrCl3 in the sample.
Since the moles of AgNO3 used is equal to the moles of CrCl3, we can use the same value obtained in Step 1.
Moles of CrCl3 = moles of AgNO3
Step 4: Calculate the mass of CrCl3 in the sample.
To do this, we need to use the molar mass of CrCl3.
Molar mass of CrCl3 = atomic mass of Cr + (3 x atomic mass of Cl)
Molar mass of CrCl3 = (52.00 g/mol) + (3 x 35.45 g/mol)
Now, calculate the mass of CrCl3:
Mass of CrCl3 = moles of CrCl3 x molar mass of CrCl3
Step 5: Calculate the mass percent of CrCl3 in the sample.
Finally, we can calculate the mass percent of CrCl3 in the sample.
Mass percent of CrCl3 = (Mass of CrCl3 / Mass of sample) x 100
Substitute the values calculated in the previous steps to find the mass percent of CrCl3 in the sample.