Question

7.02 x 10^23 molecules of X2, a ssubstance consisting of diatomic molecules, has a mass of 296 grams. Determine the atomic weight (mass of a mole of atoms) of element X.

a. 254 g/mol.
b. 296 g/mol.
c. 148 g/mol.
d. 127 g/mol.
e. 507 g/mol.

Answer 1

d. 127 g/mol.

Step-by-step explanation:

Hello!

In this case, since we have the amount of molecules of this this compound, we are able to compute the moles out there by using the Avogadro's number:

`mol=7.02x10^(23)molec*(1mol)/(6.022x10^(23)molec)=1.17mol`

Which correspond to the moles of X2. Then, by using the mass we are able to compute the molar mass of X2:

`MM=(296g)/(1.17mol)\\\\MM=254g/mol`

It means that the atomic mass of X halves the molar mass of X2, which is then d. 127 g/mol.

Best regards!