10 ml of 0.9% physiological solution sold in the pharmaceutical trade, was treated with an excess of precipitating solution of AgNO3 to 2m, leading to the formation of a white precipitate of silver chloride (AgCl), which weighed after the realization of all the steps gravimetric 0.3 g of AgCl. What is the quantity in grams of chlorides present in the sample and what is its percentage content in the sample?
You post isn't clear as to what you want. When you say "what is the grams of chlorides" I am assuming you want grams NaCl. If that isn't so please rephrase and repost the question.
0.3 g AgCl x (molar mass NaCl/molar mass AgCl) = g NaCl
% NaCl w/v = (g NaCl/10 mL) x 100 = ?
If I have understood the problem correctly this pharmaceutical supply house is not selling good stuff.
To determine the quantity of chlorides present in the sample and its percentage content, we can use the following steps:
Step 1: Convert the concentration of the physiological solution from percentage to molarity. The given concentration is 0.9%. This means that in 100 mL of the solution, there are 0.9 grams of the solute (chlorides).
- 100 mL of the physiological solution = 0.9 grams of chlorides
- 10 mL of the physiological solution = (0.9/100) * 10 grams of chlorides
- 10 mL of the physiological solution = 0.09 grams of chlorides
Step 2: Calculate the number of moles of AgCl formed.
- The weight of the precipitated AgCl is given as 0.3 grams.
- The molar mass of AgCl is approximately 143.32 g/mol.
- Hence, the number of moles of AgCl formed is 0.3 grams / 143.32 g/mol = 0.00209 moles.
Step 3: Calculate the number of moles of chlorides present in the sample.
- The molar ratio between AgCl and Cl- is 1:1, which means that 1 mole of AgCl contains 1 mole of Cl-.
- Therefore, the number of moles of chlorides present is also 0.00209 moles.
Step 4: Convert the number of moles of chlorides to grams.
- The molar mass of Cl- is approximately 35.45 g/mol.
- Hence, the quantity of chlorides present in the sample is 0.00209 moles * 35.45 g/mol = 0.074 grams.
Step 5: Calculate the percentage content of chlorides.
- The percentage content is calculated by dividing the mass of chlorides by the initial mass of the sample (0.09 grams) and then multiplying by 100.
- Percentage content = (0.074 grams / 0.09 grams) * 100 = 82.22%.
Therefore, the quantity of chlorides present in the sample is 0.074 grams, and its percentage content in the sample is approximately 82.22%.