A 1.42 g. sample of a pure compound, with formula M2SO4, was dissolved in water and treated with and excess of aqueous barium chloride, resulting in the precipitation of all the sulfate ions as barium sulfate. The precipitate was collected, dried, and found to weigh 2.33-g. Determine the atomic mass of M, and identify M.

Well, it seems like M is quite the mysterious element! Let's solve this puzzle together.

To determine the atomic mass of M, we need to calculate the number of moles of barium sulfate precipitated. We can do this by using the molar mass of barium sulfate (BaSO4).

The molar mass of BaSO4 is calculated as follows:

1 Barium (Ba) atom weighs: 137.33 g/mol
1 Sulfur (S) atom weighs: 32.07 g/mol
4 Oxygen (O) atoms weigh: 16.00 g/mol each

Thus, the molar mass of BaSO4 is:
(137.33 g/mol) + (32.07 g/mol) + 4(16.00 g/mol) = 233.39 g/mol

Now let's calculate the number of moles of BaSO4 precipitated:
2.33 g / 233.39 g/mol = 0.00998 mol

Since M2SO4 has two M atoms for every one SO4 group, that means there are 2 times more moles of M than SO4. Therefore, the number of moles of M is:
2 × 0.00998 mol = 0.01996 mol

Now we can determine the atomic mass of M by dividing the mass of M by the number of moles:
1.42 g / 0.01996 mol = 71.14 g/mol

So, the atomic mass of M is approximately 71.14 g/mol.

As for the mysterious identity of M... well, that's a secret that only M knows! Maybe M stands for "Mysterious," "Magical," or even "Mischief Maker." Who knows?

To determine the atomic mass of M and identify the element M, we need to follow the steps below:

1. Calculate the molar mass of BaSO4 (barium sulfate):
- Ba (barium) has a molar mass of 137.33 g/mol.
- S (sulfur) has a molar mass of 32.07 g/mol.
- O (oxygen) has a molar mass of 16.00 g/mol.
The molar mass of BaSO4 is then:
(1 * 137.33) + (1 * 32.07) + (4 * 16.00) = 233.38 g/mol.

2. Use stoichiometry to calculate the molar mass of M2SO4 (compound of M):
We know that 1.42 g of M2SO4 yielded 2.33 g of BaSO4.
The molar mass of BaSO4 is 233.38 g/mol.
We can set up the following ratio:
(2 moles of M2SO4 / 2.33 g of BaSO4) = (X moles of M2SO4 / 1.42 g of M2SO4).
Solving for X, we get:
X = (1.42 g of M2SO4) * (2 moles of M2SO4 / 2.33 g of BaSO4) = 1.22 moles of M2SO4.

3. Calculate the molar mass of M:
Since there are 2 moles of M2SO4 in 1.22 moles of M2SO4, we can divide the molar mass of BaSO4 by 2:
233.38 g/mol / 2 = 116.69 g/mol.

4. Identify the element M:
The atomic mass of M is approximately 116.69 g/mol. To identify the element M, we can look at the periodic table. The closest element to this atomic mass is C (carbon), which has an atomic mass of 12.01 g/mol. Therefore, the compound M2SO4 is carbon disulfate (C2SO4).

In summary, the atomic mass of M is approximately 116.69 g/mol, and the element M is carbon (C).

To determine the atomic mass of M and identify the element, we need to follow a step-by-step process. Here's how you can determine the atomic mass of M and identify the element:

1. Calculate the moles of barium sulfate precipitate using its molar mass:
Molar mass of BaSO4 = (1 x atomic mass of Ba) + (1 x atomic mass of S) + (4 x atomic mass of O)
Molar mass of BaSO4 = (1 x 137.33 g/mol) + (1 x 32.07 g/mol) + (4 x 16.00 g/mol)
Molar mass of BaSO4 = 137.33 g/mol + 32.07 g/mol + 64.00 g/mol
Molar mass of BaSO4 = 233.40 g/mol

Moles of BaSO4 = mass of precipitate / molar mass of BaSO4
Moles of BaSO4 = 2.33 g / 233.40 g/mol
Moles of BaSO4 = 0.00998 mol

2. Since barium sulfate (BaSO4) is formed by the reaction between barium chloride (BaCl2) and sulfate ions (SO4^2-), we can determine the moles of sulfate ions present in the compound:
Moles of SO4^2- = Moles of BaSO4
Moles of SO4^2- = 0.00998 mol

3. From the formula M2SO4, it's evident that two moles of M reacts with one mole of SO4^2-. Therefore, we have:
Moles of M = 2 x Moles of SO4^2-
Moles of M = 2 x 0.00998 mol
Moles of M = 0.01996 mol

4. Calculate the molar mass of M:
Molar mass of M = mass of M / moles of M
Molar mass of M = 1.42 g / 0.01996 mol
Molar mass of M = 71.14 g/mol

Therefore, the atomic mass of M is approximately 71.14 g/mol.

To identify the element M, we can refer to the Periodic Table of Elements. The element M with an atomic mass of approximately 71.14 g/mol is Cerium (Ce).

Hence, the element M in the compound M2SO4 is Cerium (Ce).