A calcium chloride solution was added to 200 g of a silver nitrate solution until the precipitation ceased. The mass of the resulting precipitate was 28.7 g. Calculate the mass fraction of silver nitrate in the original solution.
Let’s execute the solution:
1. Let’s write the equation in accordance with the condition of the problem:
m = 200 g. m = 28.7 g. W -?
2AgNO3 + CaCl2 = 2AgCl + Ca (NO3) 2 – ion exchange, precipitate of chloride is released
2. Calculation of the molar masses of substances:
M (AgNO3) = 293.8 g / mol;
M (AgCl) = 143.3 g / mol.
3. Calculate the number of moles of silver nitrate, silver chloride:
Y (AgNO3) = m / M = 200 / 293.8 = 0.68 mol;
Y (AgCl) = 0.68 mol since the amount of these substances according to the equation is 1 mol.
4. Find the theoretical mass:
m (AgCl) = Y * M = 0.68 * 143.3 = 97.44 g.
5. Let’s calculate the product yield:
W = m (practical) / m (theoretical) * 100;
W = 28.7 / 97.44 = 29.45%.
Answer: the mass fraction of the silver chloride yield was 29.45%.
One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.