A 0.4584 g sample of impure zinc chloride, ZnCl2, FW = 136.3 g/mole, was dissolved in water and excess silver nitrate was added to the solution. The mass of the dry silver chloride, AgCl, FW = 143.3 g/mole, produced was 0.8564 g. The balanced precipitation is: ZnCl2 (aq) + 2 AgNO3 (aq) --> 2 Agcl (s) + Zn(NO3)2 (aq).
1. Calculate the moles of zinc chloride present in the sample.
2. Calculate the mass of zinc chloride in the sample.
3. Calculate the percent purity of the zinc cholride in the sample.
A 0.4584 g sample of impure zinc chloride, ZnCl2, FW = 136.3 g/mole, was dissolved in water and excess silver nitrate was added to the solution. The mass of the dry silver chloride, AgCl, FW = 143.3 g/mole, produced was 0.8564 g. The balanced precipitation is: ZnCl2 (aq) + 2 AgNO3 (aq) --> 2 Agcl (s) + Zn(NO3)2 (aq).
1. Calculate the moles of zinc chloride present in the sample.
Convert mass AgCl to moles AgCl. Using the coefficients in the balanced equation, convert moles AgCl to moles ZnCl2.
2. Calculate the mass of zinc chloride in the sample.
g ZnCl2 = moles ZnCl2 x molar mas ZnCl2.
3. Calculate the percent purity of the zinc chloride in the sample.
%ZnCl2 = (mass ZnCl2/mass sample)*100 = ?
To answer these questions, we need to use stoichiometry and the given information. Let's solve each question step by step:
1. Calculate the moles of zinc chloride present in the sample:
To calculate the moles of zinc chloride, we need to use its molar mass and the mass of the sample. The molar mass of ZnCl2 is given as 136.3 g/mole.
The formula to calculate moles is:
moles = mass / molar mass
Substituting the given values:
moles of ZnCl2 = 0.4584 g / 136.3 g/mole
Calculating this will give us the moles of zinc chloride present in the sample.
2. Calculate the mass of zinc chloride in the sample:
To calculate the mass of zinc chloride in the sample, we need to use the moles calculated in the previous step and the molar mass of ZnCl2.
The formula to calculate mass is:
mass = moles * molar mass
Substituting the given values:
mass of ZnCl2 = moles * 136.3 g/mole
Calculating this will give us the mass of zinc chloride present in the sample.
3. Calculate the percent purity of the zinc chloride in the sample:
To calculate the percent purity, we need to compare the mass of the dry silver chloride produced (0.8564 g) with the mass of the zinc chloride in the sample (calculated in the previous steps).
The formula to calculate percent purity is:
percent purity = (mass of pure substance / mass of impure substance) * 100
Substituting the given values:
percent purity = (0.8564 g / mass of ZnCl2) * 100
Calculating this will give us the percent purity of the zinc chloride in the sample.
By following these steps, you can find the answers to each question.