I am supposed to calculate the mole ratio and I had given these numbers: Mg=1.153, Si=0.679, H=1.153 and O=3.07. So which number I gotta select as least number in this calculation and how will calculation be?
In order to determine the mole ratio, you need to know the number of moles for each element present in the compound. To calculate the moles, you will need the molar mass of each element.
The molar mass of Mg (magnesium) is approximately 24.31 g/mol.
The molar mass of Si (silicon) is approximately 28.09 g/mol.
The molar mass of H (hydrogen) is approximately 1.01 g/mol.
The molar mass of O (oxygen) is approximately 16.00 g/mol.
To calculate the moles, you divide the given mass of each element by its molar mass:
Moles of Mg = 1.153 g ÷ 24.31 g/mol = 0.0473 mol
Moles of Si = 0.679 g ÷ 28.09 g/mol = 0.0242 mol
Moles of H = 1.153 g ÷ 1.01 g/mol = 1.1416 mol
Moles of O = 3.07 g ÷ 16.00 g/mol = 0.1919 mol
Now, compare the moles of each element to determine the smallest value, which will be the least number used in the mole ratio. In this case, the smallest number is 0.0242 mol (moles of Si).
The mole ratio is the ratio of the moles of each element in the compound. Since the least number is moles of Si, the mole ratio would be:
Mg:Si:H:O = 0.0473 mol : 0.0242 mol : 1.1416 mol : 0.1919 mol
You can simplify this ratio by dividing each value by the moles of Si:
Mg:Si:H:O ≈ 1.95 : 1 : 47.18 : 7.93
Therefore, the mole ratio can be expressed as approximately 1.95:1:47.18:7.93 for Mg:Si:H:O.