Final answer:
To calculate the number of atoms in a sample, use the formula: Number of atoms = Number of moles x Avogadro's number. For example, 1.50 g of silver contains approximately 8.37 x 10^21 atoms. 2.00 kg of magnesium contains approximately 4.94 x 10^25 atoms. 2.34 oz of calcium contains approximately 9.92 x 10^23 atoms.
Step-by-step explanation:
To calculate the number of atoms present in a sample, we need to use the concept of moles. We can use the formula:
Number of atoms = Number of moles x Avogadro's number
a. 1.50 g of silver, Ag:
First, we need to calculate the number of moles of silver using its molar mass:
Molar mass of silver (Ag) = 107.87 g/mol
Number of moles = Mass / Molar mass = 1.50 g / 107.87 g/mol
Now, we can calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number = (1.50 g / 107.87 g/mol) x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 1.50 g of silver is approximately 8.37 x 10^21 atoms.
b. 0.0015 mole of copper, Cu:
Since 1 mole of copper contains 6.022 x 10^23 atoms, 0.0015 mole of copper contains:
Number of atoms = Number of moles x Avogadro's number = 0.0015 mole x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 0.0015 mole of copper is approximately 9.03 x 10^20 atoms.
c. 0.0015 g of copper, Cu:
First, we need to calculate the number of moles of copper using its molar mass:
Molar mass of copper (Cu) = 63.55 g/mol
Number of moles = Mass / Molar mass = 0.0015 g / 63.55 g/mol
Now, we can calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number = (0.0015 g / 63.55 g/mol) x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 0.0015 g of copper is approximately 2.23 x 10^17 atoms.
d. 2.00 kg of magnesium, Mg:
First, we need to convert the mass from kilograms to grams:
Mass = 2.00 kg x 1000 g/kg = 2000 g
Next, we need to calculate the number of moles of magnesium using its molar mass:
Molar mass of magnesium (Mg) = 24.31 g/mol
Number of moles = Mass / Molar mass = 2000 g / 24.31 g/mol
Now, we can calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number = (2000 g / 24.31 g/mol) x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 2.00 kg of magnesium is approximately 4.94 x 10^25 atoms.
e. 2.34 oz of calcium, Ca:
First, we need to convert the mass from ounces to grams:
Mass = 2.34 oz x 28.35 g/oz = 66.249 g
Next, we need to calculate the number of moles of calcium using its molar mass:
Molar mass of calcium (Ca) = 40.08 g/mol
Number of moles = Mass / Molar mass = 66.249 g / 40.08 g/mol
Now, we can calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number = (66.249 g / 40.08 g/mol) x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 2.34 oz of calcium is approximately 9.92 x 10^23 atoms.
f. 2.34 g of calcium, Ca:
First, we need to calculate the number of moles of calcium using its molar mass:
Molar mass of calcium (Ca) = 40.08 g/mol
Number of moles = Mass / Molar mass = 2.34 g / 40.08 g/mol
Now, we can calculate the number of atoms:
Number of atoms = Number of moles x Avogadro's number = (2.34 g / 40.08 g/mol) x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 2.34 g of calcium is approximately 1.37 x 10^23 atoms.
g. 2.34 moles of calcium, Ca:
Since 1 mole of calcium contains 6.022 x 10^23 atoms, 2.34 moles of calcium contains:
Number of atoms = Number of moles x Avogadro's number = 2.34 moles x 6.022 x 10^23 atoms/mol
Therefore, the number of atoms in 2.34 moles of calcium is approximately 1.41 x 10^24 atoms.