1.How many atoms are in a sample of copper with a mass of 18.46 grams?
2.How many formula units are in a sample of salt with a mass of 67.69 grams?
3.How many molecules are in a sample of water with a mass of 44.99 grams?
4.What is the mass in grams of 0.250 moles Mg?
5.How many moles are there in 48.096 grams of sulfur?
6.What is the mass of 24.6 formula units of magnesium oxide?
7.How many molecules of dinitrogen pentoxide are contained in 123.46 grams of dinitrogen pentoxide?
1. To determine the number of atoms in a sample of copper, we need to use Avogadro's number and the molar mass of copper.
Avogadro's number is 6.022 x 10^23 atoms/mol, and the molar mass of copper (Cu) is 63.55 g/mol.
To calculate the number of atoms, we can use the following formula:
Number of atoms = (mass of sample / molar mass) x Avogadro's number
In this case, for a sample of copper with a mass of 18.46 grams:
Number of atoms = (18.46 g / 63.55 g/mol) x (6.022 x 10^23 atoms/mol)
2. To determine the number of formula units in a sample of salt, we need to use Avogadro's number and the molar mass of salt.
Avogadro's number is 6.022 x 10^23 formula units/mol, and the molar mass of salt (NaCl) is 58.44 g/mol.
To calculate the number of formula units, we can use the following formula:
Number of formula units = (mass of sample / molar mass) x Avogadro's number
For a sample of salt with a mass of 67.69 grams:
Number of formula units = (67.69 g / 58.44 g/mol) x (6.022 x 10^23 formula units/mol)
3. To determine the number of molecules in a sample of water, we need to use Avogadro's number and the molar mass of water.
Avogadro's number is 6.022 x 10^23 molecules/mol, and the molar mass of water (H2O) is 18.015 g/mol.
To calculate the number of molecules, we can use the following formula:
Number of molecules = (mass of sample / molar mass) x Avogadro's number
For a sample of water with a mass of 44.99 grams:
Number of molecules = (44.99 g / 18.015 g/mol) x (6.022 x 10^23 molecules/mol)
4. To determine the mass in grams of moles of a substance, we need to use the molar mass of the substance.
In this case, we are given 0.250 moles of magnesium (Mg). The molar mass of magnesium is 24.305 g/mol.
To calculate the mass in grams, we can use the following formula:
Mass (g) = moles x molar mass
For 0.250 moles of magnesium:
Mass (g) = 0.250 moles x 24.305 g/mol
5. To determine the number of moles in a given mass of a substance, we need to use the molar mass of the substance.
In this case, we are given 48.096 grams of sulfur (S). The molar mass of sulfur is 32.06 g/mol.
To calculate the number of moles, we can use the following formula:
Moles = mass (g) / molar mass
For 48.096 grams of sulfur:
Moles = 48.096 g / 32.06 g/mol
6. To determine the mass of formula units, we need to use the molar mass of the compound.
In this case, we have 24.6 formula units of magnesium oxide (MgO). The molar mass of magnesium oxide is 40.30 g/mol.
To calculate the mass, we can use the following formula:
Mass = number of formula units x molar mass
For 24.6 formula units of magnesium oxide:
Mass = 24.6 x 40.30 g/mol
7. To determine the number of molecules in a sample of dinitrogen pentoxide, we need to use Avogadro's number and the molar mass of dinitrogen pentoxide.
Avogadro's number is 6.022 x 10^23 molecules/mol, and the molar mass of dinitrogen pentoxide (N2O5) is 108.01 g/mol.
To calculate the number of molecules, we can use the following formula:
Number of molecules = (mass of sample / molar mass) x Avogadro's number
For 123.46 grams of dinitrogen pentoxide:
Number of molecules = (123.46 g / 108.01 g/mol) x (6.022 x 10^23 molecules/mol)
1. To determine the number of atoms in a sample of copper, we need to use Avogadro's number and the molar mass of copper (Cu).
The molar mass of copper is 63.55 grams/mol.
We can set up a proportion:
Number of atoms / Molar mass of copper = Mass of sample / Mass of one mole of copper
Number of atoms / 63.55 g/mol = 18.46 g / 1 mol
Number of atoms = (18.46 g / 63.55 g/mol) * (6.022 x 10^23 atoms/mol)
Using a calculator, we can calculate the number of atoms. The answer is approximately 5.59 x 10^22 atoms.
2. To determine the number of formula units in a sample of salt (NaCl), we need to use Avogadro's number and the molar mass of salt.
The molar mass of salt (NaCl) is 58.44 grams/mol.
We can set up a proportion:
Number of formula units / Molar mass of salt = Mass of sample / Mass of one mole of salt
Number of formula units / 58.44 g/mol = 67.69 g / 1 mol
Number of formula units = (67.69 g / 58.44 g/mol) * (6.022 x 10^23 formula units/mol)
Using a calculator, we can calculate the number of formula units. The answer is approximately 6.99 x 10^23 formula units.
3. To determine the number of molecules in a sample of water (H2O), we need to use Avogadro's number and the molar mass of water.
The molar mass of water (H2O) is 18.01528 grams/mol.
We can set up a proportion:
Number of molecules / Molar mass of water = Mass of sample / Mass of one mole of water
Number of molecules / 18.01528 g/mol = 44.99 g / 1 mol
Number of molecules = (44.99 g / 18.01528 g/mol) * (6.022 x 10^23 molecules/mol)
Using a calculator, we can calculate the number of molecules. The answer is approximately 1.50 x 10^24 molecules.
4. To calculate the mass in grams of a given number of moles of magnesium (Mg), we need to multiply the number of moles by the molar mass of magnesium.
The molar mass of magnesium (Mg) is 24.305 grams/mol.
Mass (g) = Number of moles * Molar mass (g/mol)
Mass (g) = 0.250 mol * 24.305 g/mol
Using a calculator, we can calculate the mass. The answer is approximately 6.08 grams.
5. To determine the number of moles in a given mass of sulfur (S), we need to divide the mass by the molar mass of sulfur.
The molar mass of sulfur (S) is 32.06 grams/mol.
Number of moles = Mass (g) / Molar mass (g/mol)
Number of moles = 48.096 g / 32.06 g/mol
Using a calculator, we can calculate the number of moles. The answer is approximately 1.50 moles.
6. To calculate the mass of a given number of formula units of magnesium oxide (MgO), we need to multiply the number of formula units by the molar mass of magnesium oxide.
The molar mass of magnesium oxide (MgO) is 40.31 grams/mol.
Mass (g) = Number of formula units * Molar mass (g/mol)
Mass (g) = 24.6 formula units * 40.31 g/mol
Using a calculator, we can calculate the mass. The answer is approximately 992.226 grams.
7. To determine the number of molecules of dinitrogen pentoxide (N2O5) in a given mass, we need to use Avogadro's number and the molar mass of dinitrogen pentoxide.
The molar mass of dinitrogen pentoxide (N2O5) is 108.0114 grams/mol.
We can set up a proportion:
Number of molecules / Molar mass of dinitrogen pentoxide = Mass of sample / Mass of one mole of dinitrogen pentoxide
Number of molecules / 108.0114 g/mol = 123.46 g / 1 mol
Number of molecules = (123.46 g / 108.0114 g/mol) * (6.022 x 10^23 molecules/mol)
Using a calculator, we can calculate the number of molecules. The answer is approximately 6.86 x 10^23 molecules.