Determine (a) the total number of Cl atoms in 125mL of liquid CCl4 (d= 1.589g/mL) and (b) the number of grams of carbon in 215 of sucrose, C12H22O11.
To determine the total number of Cl atoms in 125 mL of liquid CCl4 and the number of grams of carbon in 215 g of sucrose, we need to use basic concepts from chemistry such as molar mass, Avogadro's number, and stoichiometry. The steps to solve these problems are as follows:
(a) Total number of Cl atoms in CCl4:
1. Start by calculating the number of moles of CCl4 using the given density.
- Density (d) = mass (m) / volume (V)
- Rearrange the equation to solve for mass: mass = density * volume
- mass = 1.589 g/mL * 125 mL = 198.625 g
- Convert mass to moles using the molar mass of CCl4.
2. Calculate the molar mass of CCl4:
- Molar mass of CCl4 = atomic mass of carbon + (atomic mass of chlorine * 4)
- Molar mass of CCl4 = 12.01 g/mol + (35.45 g/mol * 4) = 153.82 g/mol
3. Convert mass to moles using the molar mass:
- Moles = mass / molar mass = 198.625 g / 153.82 g/mol ≈ 1.29 mol
4. Determine the number of Cl atoms using Avogadro's number:
- Avogadro's number (NA) = 6.022 * 10^23 atoms/mol
- Number of Cl atoms = Moles * NA = 1.29 mol * 6.022 * 10^23 atoms/mol = 7.771 * 10^23 Cl atoms
Therefore, there are approximately 7.771 * 10^23 Cl atoms in 125 mL of liquid CCl4.
(b) Number of grams of carbon in sucrose:
1. Start by calculating the number of moles of sucrose using its molar mass.
- Molar mass of sucrose (C12H22O11) = [atomic mass of carbon * 12] + [atomic mass of hydrogen * 22] + [atomic mass of oxygen * 11]
- Molar mass of sucrose = (12.01 g/mol * 12) + (1.01 g/mol * 22) + (16.0 g/mol * 11) = 342.34 g/mol
2. Convert mass to moles using the molar mass:
- Moles = mass / molar mass = 215 g / 342.34 g/mol ≈ 0.628 mol
3. Determine the mass of carbon using stoichiometry.
- Sucrose (C12H22O11) has 12 carbon atoms per molecule.
- Mass of carbon = Moles of sucrose * molar mass of carbon
- Mass of carbon = 0.628 mol * 12.01 g/mol ≈ 7.53 g
Therefore, there are approximately 7.53 grams of carbon in 215 grams of sucrose.