What is the emperical formula of a compound that contains 0.04moles of sodium, 0.04moles of sulphur, and 0.06moles of oxygen?
Divide by the smallest to get 1.00 for the lowest number.
0.04/0.04 = 1.00
0.04/0.04 = 1.00
0.06/-0.04 = 1.50
So we would write NaSO1.5 BUT we want whole numbers; therefore, we can multiply by 2 to obtain 2:2:3 for Na2S2O3 which is sodium thiosulfate.
To determine the empirical formula of a compound, we need to find the simplest and most reduced ratio of atoms in the compound.
In this case, we are given the moles of each element present in the compound: 0.04 moles of sodium (Na), 0.04 moles of sulphur (S), and 0.06 moles of oxygen (O).
Step 1: Find the smallest whole number ratio:
Divide each mole value by the smallest mole value among the elements. In this case, the smallest mole value is 0.04 moles.
0.04 moles of Na / 0.04 moles = 1
0.04 moles of S / 0.04 moles = 1
0.06 moles of O / 0.04 moles = 1.5
Step 2: Convert the ratio to the closest whole numbers:
Multiply all the numbers by a factor that makes them the closest whole numbers possible. In this case, multiplying by 2 will give us whole numbers.
1 x 2 = 2
1 x 2 = 2
1.5 x 2 = 3
Step 3: Write down the empirical formula:
The empirical formula is the simplest ratio of atoms in the compound. Therefore, the empirical formula for the compound containing 0.04 moles of sodium, 0.04 moles of sulphur, and 0.06 moles of oxygen is Na2S2O3.
The empirical formula indicates that for every two atoms of sodium, there are two atoms of sulphur and three atoms of oxygen in the compound.