In a typical synthesis reaction, 0.142 g of chlorine gas is reacted with an unkown elemnt X to form a compound with the formula XCl3. If the final product has a mass of 0.178 g, what is the atomic mass of the unknown element?

Answer 1

3Cl2 + 2X ==>2XCl3

mols Cl2 = g/molar mass = 0.142/molar mass Cl2.

mols XCl3 = mols Cl2 x (2 mol XCl3/3 mols Cl2)= xx

mols XCl3 = g/molar mass or rearrange to
molar mass = g/mols
Then knowing molar mass and mass Cl3, determine mass X which will be the atomic mass. Look on the periodic table to determine the metal.
Check my work.

Answer 2

The guy posting as DrBob222 attempts to make the student do the question out themselves by posting the structure of the question. I hope this guy realizes his psychobabble is not understandable and that he is the bane of students everywhere.