find the empirical formula for a compound which contains 32.8% chromium and 67.2% of chlorine
To determine the empirical formula, we first need to determine the ratio of the elements present in the compound.
Step 1: Convert the percentages to grams:
Assume we have 100g of the compound.
Chromium: 32.8g
Chlorine: 67.2g
Step 2: Convert the grams to moles:
Molar mass of Chromium (Cr) = 52.00 g/mol
Moles of Chromium = 32.8g / 52.00 g/mol = 0.631 moles
Molar mass of Chlorine (Cl) = 35.45 g/mol
Moles of Chlorine = 67.2g / 35.45 g/mol = 1.894 moles
Step 3: Find the ratio of the moles by dividing each value by the smallest number:
Since Chromium has 0.631 moles and Chlorine has 1.894 moles, divide each by 0.631:
Chromium (Cr): 0.631 / 0.631 = 1 mole
Chlorine (Cl): 1.894 / 0.631 = 3 moles
Step 4: Determine the empirical formula:
The empirical formula is determined by the lowest whole number ratio of the elements present. Since Chromium has a coefficient of 1 and Chlorine has a coefficient of 3, the empirical formula is CrCl3.