. A liter of air contains 9.2 × 10−4 mol argon. What is the mass of Ar in a liter of air? (AM=39.948g/mol) (Ans: 0.037 g Ar)3.Carbon atoms have a diameter of 1.5x10-8 cm. If carbon atoms were laid in a row 3.0 cm long, what would be the total mass of carbon? Deriving Number of Atoms from Mass for an Element3. Copper is commonly used to fabricate electrical wire. How many copper atoms are in 5.00 g of copper wire? (AM=63.55 g/mol)(Ans: 4.74 x1022 atoms of Cu)
1. First, we need to calculate the mass of argon in a liter of air. We know that 9.2 × 10^-4 mol of argon is present in one liter of air.
Using the molar mass of argon (39.948 g/mol), we can calculate the mass of argon in one liter of air:
Mass of Ar = (9.2 × 10^-4 mol) x (39.948 g/mol) = 0.0368 g Ar
Therefore, the mass of Ar in a liter of air is 0.037 g Ar.
2. To calculate the total mass of carbon in a row 3.0 cm long, we first need to determine the number of carbon atoms in this row.
Given that the diameter of a carbon atom is 1.5x10^-8 cm, we can calculate the number of atoms:
Number of atoms = Length of row / Diameter of one atom
Number of atoms = 3.0 cm / 1.5x10^-8 cm = 2.0x10^8 atoms
Since we are dealing with carbon atoms, and the atomic mass of carbon is 12.01 g/mol, we can calculate the total mass of carbon:
Total mass of carbon = Number of atoms x Atomic mass of carbon
Total mass of carbon = 2.0x10^8 atoms x 12.01 g/mol = 2.40x10^9 g
Therefore, the total mass of carbon in a row 3.0 cm long is 2.40x10^9 g.
3. To determine the number of copper atoms in 5.00 g of copper wire, we can use the formula:
Number of atoms = (Mass of sample / Atomic mass of copper) x Avogadro's number
Number of atoms = (5.00 g / 63.55 g/mol) x 6.022x10^23 atoms/mol
Number of atoms = 4.74x10^22 atoms
Therefore, there are 4.74x10^22 atoms of copper in 5.00 g of copper wire.