Trichloromethane consists of10.05% carbon 0.83% hydrogen and 82.12% chlorine.Its relative molar mass is 119.5% .Find its molecular mass(Cl=35.5,C=12,H=1)
Relative molar mass 119%?
Trichloromethane consists of10.05% carbon 0.83% hydrogen and 82.12% chlorine.Its relative molar mass is 119.5% .Find its molecular mass(Cl=35.5,C=12,H=1)
To find the molecular mass of trichloromethane (CHCl3), you need to calculate the sum of the atomic masses of all its constituent atoms.
Given:
Carbon (C) atom has an atomic mass of 12.
Hydrogen (H) atom has an atomic mass of 1.
Chlorine (Cl) atom has an atomic mass of 35.5.
First, let's calculate the number of moles of each element in the compound:
1. Carbon (C):
To find the moles of carbon in trichloromethane, use the given percentage:
10.05% means there are 10.05 grams of carbon for every 100 grams of trichloromethane.
Next, convert grams of carbon to moles of carbon using the atomic mass:
Moles of carbon = grams of carbon / atomic mass of carbon
Moles of carbon = 10.05 g / 12 g/mol ≈ 0.8375 moles
2. Hydrogen (H):
To find the moles of hydrogen in trichloromethane, use the given percentage:
0.83% means there are 0.83 grams of hydrogen for every 100 grams of trichloromethane.
Next, convert grams of hydrogen to moles of hydrogen using the atomic mass:
Moles of hydrogen = grams of hydrogen / atomic mass of hydrogen
Moles of hydrogen = 0.83 g / 1 g/mol = 0.83 moles
3. Chlorine (Cl):
To find the moles of chlorine in trichloromethane, use the given percentage:
82.12% means there are 82.12 grams of chlorine for every 100 grams of trichloromethane.
Next, convert grams of chlorine to moles of chlorine using the atomic mass:
Moles of chlorine = grams of chlorine / atomic mass of chlorine
Moles of chlorine = 82.12 g / 35.5 g/mol ≈ 2.3149 moles
Now that we have the moles of each element, we can calculate the molecular mass by summing the atomic masses of each atom in the compound:
Molecular mass = (moles of carbon × atomic mass of carbon) + (moles of hydrogen × atomic mass of hydrogen) + (moles of chlorine × atomic mass of chlorine)
Molecular mass = (0.8375 moles × 12 g/mol) + (0.83 moles × 1 g/mol) + (2.3149 moles × 35.5 g/mol)
Molecular mass ≈ 12.098 + 0.83 + 82.164795
Molecular mass ≈ 95.092 g/mol
Therefore, the molecular mass of trichloromethane (CHCl3) is approximately 95.092 g/mol.