what is the empirical formula for a compund with 26.2 g N, 7.5 g H, and 66.3 g Cl?
26.2 g of N*(1 mole of N/14.01g)= moles of N=1.87 moles of N
7.5 g of H *(1 mole of H/1.007 g of H)= moles of H=7.45 moles of H
66.3 g of Cl *(1 mole of Cl/35.45g of Cl)= moles of Cl=1.87 moles of Cl
take the lowest number of moles, and divide by the others.
N=1.87/1.87=1
H=7.45/1.87=3.98=4
Cl=1.87/1.87=1
To determine the empirical formula of a compound, you need to convert the given masses of each element into moles and then find the ratio of the moles of each element. Here's how you can do it:
Step 1: Convert the masses of each element to moles using their molar masses:
- N (Nitrogen): Molar mass = 14.01 g/mol
Moles of N = Mass of N / Molar mass of N = 26.2 g / 14.01 g/mol = 1.87 mol
- H (Hydrogen): Molar mass = 1.01 g/mol
Moles of H = Mass of H / Molar mass of H = 7.5 g / 1.01 g/mol = 7.43 mol
- Cl (Chlorine): Molar mass = 35.45 g/mol
Moles of Cl = Mass of Cl / Molar mass of Cl = 66.3 g / 35.45 g/mol = 1.87 mol
Step 2: Determine the simplest whole number ratio between the moles of each element by dividing the moles of each element by the smallest mole value:
- Divide the moles of N by 1.87 (which is the lowest mole value):
Moles of N / 1.87 mol = 1.87 mol / 1.87 mol = 1 mol
- Divide the moles of H by 1.87:
Moles of H / 1.87 mol = 7.43 mol / 1.87 mol = 3.97 mol
- Divide the moles of Cl by 1.87:
Moles of Cl / 1.87 mol = 1.87 mol / 1.87 mol = 1 mol
Step 3: Determine the empirical formula using the whole number ratio:
The empirical formula for the compound is N1H4Cl1.