Calculate the number of moles and atoms.
A)64 gm of O2
B)58.9gm of CI
C)90.5gm of (NH4)2SO4
D)243gm of Mg2
Please help i have NO CLUE HOW TO DO THIS THANKS!!!
# moles = grams/molar mass.
Sure! I can help you with calculating the number of moles and atoms for each given substance. To do this, we will use the concepts of molar mass and Avogadro's number.
First, let's calculate the number of moles. The number of moles can be calculated using the formula:
Number of moles = Mass of substance (in grams) / Molar mass of substance
A) Oxygen gas (O2):
Given: Mass = 64 gm
Since oxygen gas (O2) consists of two oxygen atoms, we need to find the molar mass of O2. The molar mass of oxygen (O) is 16 g/mol.
So, the molar mass of O2 = 2 * 16 g/mol = 32 g/mol.
Number of moles = 64 gm / 32 g/mol = 2 moles
B) Chlorine (CI):
Given: Mass = 58.9 gm
The molar mass of chlorine (CI) is 35.5 g/mol.
Number of moles = 58.9 gm / 35.5 g/mol ≈ 1.66 moles
C) Ammonium sulfate ((NH4)2SO4):
Given: Mass = 90.5 gm
The molar mass of (NH4)2SO4 can be calculated by summing up the molar mass of all the atoms in it.
Molar mass of N = 14 g/mol
Molar mass of H = 1 g/mol
Molar mass of S = 32 g/mol
Molar mass of O = 16 g/mol
Molar mass of (NH4)2SO4 = (2 * 14 g/mol) + (8 * 1 g/mol) + 32 g/mol + (4 * 16 g/mol) = 132 g/mol.
Number of moles = 90.5 gm / 132 g/mol ≈ 0.685 moles
D) Magnesium (Mg):
Given: Mass = 243 gm
The molar mass of magnesium (Mg) is 24.3 g/mol.
Number of moles = 243 gm / 24.3 g/mol = 10 moles
Now that we have found the number of moles, let's calculate the number of atoms. We can do this by multiplying the number of moles by Avogadro's number, which is approximately 6.022 x 10^23.
Number of atoms = Number of moles * Avogadro's number
For example, in case A (O2):
Number of atoms = 2 moles * 6.022 x 10^23 = 12.044 x 10^23 atoms
Similarly, you can calculate the number of atoms for the remaining substances using the number of moles you have calculated.
I hope this explanation was helpful! Let me know if you have any other questions.