In the experiment 0.500 g of copper reacted with oxygen to give 0.563 g of copper oxide. What is the empirical formula of the oxide expressed as a chemical formula?
Sn2O3
To determine the empirical formula of the copper oxide, you first need to determine the number of moles of copper and oxygen.
Step 1: Calculate the number of moles of copper:
The molar mass of copper (Cu) is 63.55 g/mol. The mass of copper is given as 0.500 g.
Number of moles of copper = (mass of copper) / (molar mass of copper)
= 0.500 g / 63.55 g/mol
= 0.0078687739 mol
Step 2: Calculate the number of moles of oxygen:
The molar mass of oxygen (O) is 16.00 g/mol. The total mass of copper oxide is given as 0.563 g.
Number of moles of oxygen = (mass of copper oxide - mass of copper) / (molar mass of oxygen)
= (0.563 g - 0.500 g) / 16.00 g/mol
= 0.0039375 mol
Step 3: Find the mole ratio between copper and oxygen:
To find the empirical formula, we need to find the simplest, whole-number ratio between the moles of copper and oxygen.
Divide the number of moles of each element by the smallest number of moles.
In this case, the smallest number of moles is 0.0039375 mol (oxygen).
Moles of Cu = 0.0078687739 mol / 0.0039375 mol = 2
Moles of O = 0.0039375 mol / 0.0039375 mol = 1
Step 4: Write the empirical formula using the mole ratio:
The empirical formula of the copper oxide is Cu2O.
Therefore, the empirical formula of the copper oxide is Cu2O.
To determine the empirical formula of the oxide, we need to find the ratio between the number of atoms of copper (Cu) and oxygen (O) in the compound.
Step 1: Find the mass of copper (Cu)
Given that 0.500 g of copper reacted, the mass of copper is 0.500 g.
Step 2: Find the mass of oxygen (O)
Given that 0.563 g of copper oxide was obtained, and we assume that all the oxygen in the compound comes from the copper oxide, the mass of oxygen is the difference between the mass of the copper oxide and the mass of copper.
Mass of oxygen = Mass of copper oxide - Mass of copper
Mass of oxygen = 0.563 g - 0.500 g
Mass of oxygen = 0.063 g
Step 3: Convert mass to moles
To compare the number of atoms in different elements, we need to convert their mass to moles using the molar mass.
The molar mass of copper (Cu) is 63.55 g/mol, and the molar mass of oxygen (O) is 16.00 g/mol.
Moles of Cu = Mass of Cu / Molar mass of Cu
Moles of Cu = 0.500 g / 63.55 g/mol
Moles of Cu = 0.0079 mol
Moles of O = Mass of O / Molar mass of O
Moles of O = 0.063 g / 16.00 g/mol
Moles of O = 0.0039 mol
Step 4: Find the mole ratio
To determine the empirical formula, we need to find the simplest whole number ratio between the moles of copper and oxygen. Divide both moles by the smaller value.
Moles ratio = Moles of Cu / Moles of O
Moles ratio = 0.0079 mol / 0.0039 mol
Moles ratio = 2
The empirical formula is Cu2O, which means the compound consists of two copper atoms and one oxygen atom.
..........Cu + O2 ==> CuxOy
I.....0.500g...0.......0
C..............x.........
E.....0.500+x..-x.....0.563
Therefore, g Cu = 0.500
grams oxygen = 0.0.063
mols Cu = 0.500/atomic mass Cu = ?
mols O = 0.063/16 = ?
Now find the ratio of the mols to each other with the smaller number being 1.00.
Post your work if you get stuck.