A metal X with relative atomic mass 56 forms an oxide with formula X2O3 . All grams of the metal combine with 105 of CO2 (O=16)
To determine the molar mass and identity of the metal X, we can use the given information that all grams of the metal X combine with 105 grams of CO2.
1. Calculate the molar mass of CO2:
The molar mass of carbon (C) is 12 g/mol, and the molar mass of oxygen (O) is 16 g/mol. Since there are two oxygen atoms in CO2, the molar mass of CO2 is:
(12 g/mol for carbon) + (16 g/mol for each oxygen × 2) = 44 g/mol
2. Determine the molar amount of CO2:
The given mass of CO2 is 105 g. Convert this to moles by dividing by the molar mass of CO2:
105 g CO2 ÷ 44 g/mol = 2.386 mol CO2
3. Using the stoichiometry of the equation X + CO2 → X2O3 + C, determine the molar amount of metal X:
From the balanced equation, we can see that the stoichiometric ratio between CO2 and X is 1:1. Therefore, the molar amount of metal X is also 2.386 mol.
4. Calculate the molar mass of X:
The molar amount of X is equal to the molar mass of X in grams. Therefore, the molar mass of X is:
105 g ÷ 2.386 mol = 44 g/mol
The molar mass of metal X is determined to be 44 g/mol. Given that the relative atomic mass of X is 56, we can conclude that the metal X is twice as heavy as its molar mass. This suggests that the metal X has two atoms per formula unit.
Therefore, the metal X with a relative atomic mass of 56 and the oxide X2O3 forms contains one mole of X atoms with a molar mass of 44 g/mol.