Question

# Calculate the theoretical yield of the solid precipitate. Show your work. mass of CaCl2 =2.0 g...

1. Calculate the theoretical yield of the solid precipitate. Show your work.

mass of CaCl2 =2.0 g

Molar mass of CaCl2 = 110.98 g/mol

Moles of CaCl2 = 2.0 g * 1 mol/110.98g = 0.018 mol

Mass of K2Co3 =2.0 g

Molar mass of K2Co3 = 138.205 g/mol

Moles of K2Co3 =2.0 g * 1 mol/ 138.205g =0.0145 moles

According to balanced equation 1mole of CaCl2 reacts with 1 mole of K2CO3

Thus, 0.018 moles of CaCl2 will react with = 0.018 moles of K2CO3

Thus, 0.0145 moles of K2CO3 will produce 0.0145 moles of CaCO3

Molar mass of CaCO3 = 100.0869 g/mol

Theoretical yield of CaCO3 = moles of CaCO3 * molar mass of CaCO3

Theoretical yield of CaCO3 = 0.0145 moles * 100.0869 g/mol =1.45 g

1. Use Question 1 to calculate the percent yield of the solid precipitate. Show your work.

1.45 g = 1.45/100.0869

=0.0144 moles

Therefore, % yield= 0.0144/0.018

=80%

1. Based on your yield of calcium carbonate, calculate the mass of calcium present in the original solution.
2. Analyze the data and use your yield of calcium carbonate to determine the experimental concentration of calcium chloride in the solution that you made in steps 6 and 7. Show all calculations and report in % wt/v concentration.
3. Calculate the theoretical concentration of calcium chloride in the solution that you made up in steps 6 and 7. Show all calculations and report in % wt/v concentration.
4. Using your answers from questions 4 and 5, create a bar graph comparing the theoretical to experimental percent concentrations of calcium chloride in the solution. Then, calculate percent error between the two concentrations.

Table 1: Data and Observations

 Material Mass CaCl2 2.0 K2CO3 2.0 Filter Paper 2.3 Watch Glass 37.3 Filter Paper + Watch Glass + Precipitate 8.6 Precipitate 1.7

Table 2: Mass of CaCl2 after 24 Hours

 Initial Observations 24 hour Observation weigh Boat 2.2 5.4 CaCl2 2.0 3.2

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