8.10 g metal combines with 7.20g of oxygen to form X2O3. What is the relativ
e mass of X
4X + 3O2 ==> 2X2O3
mols O2 = 7.2/32 = about 0.225
mols X = 0.225 x 4/3 = about o.9
mols X = grams/molar mass. You know g and mols, solve for molar mass
To determine the relative mass of X in X2O3, we need to find the number of moles of X in the compound.
Step 1: Find the number of moles of metal (X).
To find the number of moles, we use the formula:
moles = mass / molar mass
The molar mass of metal X is not given, so we can't directly calculate the moles of X. However, we can find the number of moles of oxygen (O) and use that information to determine the moles of X.
Step 2: Find the number of moles of oxygen (O).
To calculate the moles of oxygen, we use the given mass and the molar mass of oxygen (16.00 g/mol):
moles of O = mass of O / molar mass of O
= 7.20 g / 16.00 g/mol
= 0.45 mol
Step 3: Use the mole ratio to find the number of moles of X.
The stoichiometry of the formula X2O3 tells us that there are 2 moles of X for every 3 moles of O. Using this ratio, we can calculate the moles of X:
moles of X = (moles of O * 2) / 3
= (0.45 mol * 2) / 3
= 0.30 mol
Step 4: Find the relative mass of X.
To find the relative mass of X, we divide the mass of X by the number of moles of X:
relative mass of X = mass of X / moles of X
= 8.10 g / 0.30 mol
= 27 g/mol
Therefore, the relative mass of X in X2O3 is 27 g/mol.