[Chem] Determining Masses from Concentration

[dt_]

Homework Statement

In lab, a student decides to analyze a 0.6118 g sample containing only magnesium chloride and sodium chloride. He does this by adding 145 milliliters of 0.1006 M silver nitrate. A precipitate, silver chloride, is formed, which has a mass of 1.7272 grams. Using this data, calculate the mass of each of the original sample's components.

Homework Equations

M = mol / L

$$MgCl_{2} + NaCl + AgNO_{3}$$ ...?

The Attempt at a Solution

I'm not really sure where to start here; my instinct is to multiply the volume of the silver nitrate by its molarity to get the number of moles. But I'm not sure what to do next, and I don't know what the products of the reaction are, other than the silver chloride precipitate. And besides, how would I able to find out how much mass there is of the individual components in the original sample if the problem only gives the total mass of these two components? Can anyone help me out? (Thanks in advance!

 

[chemisttree]

Homework Statement

In lab, a student decides to analyze a 0.6118 g sample containing only magnesium chloride and sodium chloride. He does this by adding 145 milliliters of 0.1006 M silver nitrate. A precipitate, silver chloride, is formed, which has a mass of 1.7272 grams. Using this data, calculate the mass of each of the original sample's components.

Homework Equations

M = mol / L

$$MgCl_{2} + NaCl + AgNO_{3}$$ ...?

The Attempt at a Solution

I'm not really sure where to start here; my instinct is to multiply the volume of the silver nitrate by its molarity to get the number of moles. But I'm not sure what to do next, and I don't know what the products of the reaction are, other than the silver chloride precipitate. And besides, how would I able to find out how much mass there is of the individual components in the original sample if the problem only gives the total mass of these two components? Can anyone help me out? (Thanks in advance!

Start by writing out the precipitation reaction. This will give you the ratio of moles of silver chloride to moles of magnesium chloride plus sodium chloride.
Do you know how to determine the number of moles of silver chloride produced with the given data?
Hint: more data is given to you than you need to answer this question. Which data is unnecessary?

 

[Blueshift5]

To solve this problem, you will need to use the concept of stoichiometry, which is the relationship between the amounts of reactants and products in a chemical reaction. In this case, the reaction is between magnesium chloride (MgCl2) and silver nitrate (AgNO3), and the products are silver chloride (AgCl) and sodium nitrate (NaNO3). The balanced equation for this reaction is:

MgCl2 + 2AgNO3 → 2AgCl + Mg(NO3)2

From this equation, we can see that for every 1 mole of MgCl2, 2 moles of AgCl will be produced. This means that the number of moles of AgCl formed in the reaction is equal to the number of moles of MgCl2 in the original sample.

To find the number of moles of AgCl formed, we can use the formula M = mol/L, where M is the molarity, mol is the number of moles, and L is the volume in liters. In this case, we know the molarity of the silver nitrate (0.1006 M) and the volume of silver nitrate used (145 mL or 0.145 L). Plugging these values into the formula, we get:

0.1006 M = mol / 0.145 L

Solving for mol, we get:

mol = 0.1006 M x 0.145 L = 0.0146 mol

Since 2 moles of AgCl are produced for every 1 mole of MgCl2, we can say that 0.0146 mol of AgCl is equivalent to 0.0073 mol of MgCl2.

Now, to find the mass of MgCl2 in the original sample, we can use the molar mass of MgCl2, which is 95.211 g/mol. Multiplying the number of moles by the molar mass, we get:

0.0073 mol x 95.211 g/mol = 0.6951 g of MgCl2

To find the mass of NaCl in the original sample, we can use the fact that the total mass of the sample is 0.6118 g and we already know that the mass of MgCl2 is 0.6951 g. So, the mass of NaCl can be calculated by subtracting the mass of MgCl