Question

Question #99479

Answer 1

Carbon `(C)`

Explanation:

A "chloride" by definition is some compound with chlorine in it. So therefore, your mystery element and chlorine form a compound `XCl` with molar mass `47.5 "g"`.

We also know that the molar mass of any compound is the sum of the molecular weights of its constituent elements. Therefore, we have:

`M_x + M_(Cl) = M_(XCl)`

The molar mass of `Cl` is `35.45 "g"`. Plugging that, along with the compound's molar mass, gives:

`M_x + 35.45 = 47.5`.

Solving for `M_x` is now simple:

`M_x = 47.5 - 35.45 = 12.05 "g"`

If you look on a periodic table, you'll see that that molar mass is closest to that of carbon. So carbon is your mystery element.

However, `"C"Cl` is not a compound that exists. `"C"Cl_4` does, but not `"C"Cl`. So either this question has assumed a made-up compound, or the problem statement has an incorrect molar mass. Regardless, this is the process you would follow.

What if you had to take into account the possibility of multiple `Cl` atoms, or even multiple atoms of they mystery element, in the compound? Well, then you'd need to at least be given a generic formula (ex.`X_2Cl_4`) in order to solve.

Hope that helps :)