How many Cl atoms are in a 2.54g sample of CCl4?
To determine the number of Cl (chlorine) atoms in a given sample of CCl4 (carbon tetrachloride), you need to use the concept of moles and Avogadro's number. Here's how you can calculate it step by step:
1. Determine the molar mass of CCl4:
Carbon (C) has a molar mass of approximately 12.01 g/mol, and Chlorine (Cl) has a molar mass of approximately 35.45 g/mol. Since there are four chlorine atoms in one molecule of CCl4, we can calculate the molar mass as follows:
Molar mass of CCl4 = (molar mass of C) + 4 × (molar mass of Cl) = 12.01 g/mol + 4 × 35.45 g/mol = 12.01 g/mol + 141.8 g/mol = 153.81 g/mol.
2. Calculate the number of moles of CCl4:
Use the formula:
moles = mass / molar mass
Given that the mass is 2.54 g and the molar mass is 153.81 g/mol:
moles of CCl4 = 2.54 g / 153.81 g/mol ≈ 0.0165 mol.
3. Determine the number of Cl atoms:
In one molecule of CCl4, there are four Cl atoms. So, to find the number of Cl atoms in the given sample, multiply the number of moles of CCl4 by the number of Cl atoms per molecule:
Number of Cl atoms = moles of CCl4 × 4 = 0.0165 mol × 4 ≈ 0.066 atoms.
However, it is important to note that the number of atoms cannot be in decimal form. Therefore, you would typically round it to the nearest whole number. In this case, it would be rounded down to zero because 0.066 atoms does not make sense. So, you can conclude that there are zero Cl atoms in a 2.54g sample of CCl4.