How many atoms or molecules are in 5.0 moles of the following?
a) O
b) N
c) MgCl2
d) C2H3NO
To determine the number of atoms or molecules in a given number of moles, we can use Avogadro's number, which states that one mole of any substance contains 6.022 x 10^23 entities (atoms, molecules, ions, etc).
a) O (oxygen)
5.0 moles of O contains 5.0 x (6.022 x 10^23) = 3.011 x 10^24 oxygen atoms.
b) N (nitrogen)
5.0 moles of N contains 5.0 x (6.022 x 10^23) = 3.011 x 10^24 nitrogen atoms.
c) MgCl2 (magnesium chloride)
1 mole of MgCl2 contains 1 x (6.022 x 10^23) = 6.022 x 10^23 formula units of MgCl2.
5.0 moles of MgCl2 contains 5.0 x (6.022 x 10^23) = 3.011 x 10^24 formula units of MgCl2.
Since each formula unit of MgCl2 contains 1 magnesium atom (Mg) and 2 chloride atoms (Cl), the total number of atoms is:
3.011 x 10^24 Mg atoms + 2 x 3.011 x 10^24 Cl atoms = 3.011 x 10^24 Mg atoms + 6.022 x 10^24 Cl atoms.
d) C2H3NO (acetonitrile)
1 mole of C2H3NO contains 1 x (6.022 x 10^23) = 6.022 x 10^23 formula units of C2H3NO.
5.0 moles of C2H3NO contains 5.0 x (6.022 x 10^23) = 3.011 x 10^24 formula units of C2H3NO.
Since each formula unit of C2H3NO contains 2 carbon atoms (C), 3 hydrogen atoms (H), 1 nitrogen atom (N), and 1 oxygen atom (O), the total number of atoms is:
2 x 3.011 x 10^24 C atoms + 3 x 3.011 x 10^24 H atoms + 1 x 3.011 x 10^24 N atoms + 1 x 3.011 x 10^24 O atoms.
To find the number of atoms or molecules in a given amount of substance, you can use Avogadro's number. Avogadro's number is defined as 6.022 x 10^23, which represents the number of particles (atoms, molecules, or ions) in one mole of a substance.
Let's calculate the number of atoms or molecules in each case:
a) O (oxygen):
Since we have 5.0 moles of O, we can multiply this by Avogadro's number:
Number of atoms = 5.0 moles x 6.022 x 10^23 atoms/mole
Number of atoms = 3.011 x 10^24 atoms
b) N (nitrogen):
Similar to the previous case, we can multiply the number of moles by Avogadro's number:
Number of atoms = 5.0 moles x 6.022 x 10^23 atoms/mole
Number of atoms = 3.011 x 10^24 atoms
c) MgCl2 (magnesium chloride):
To calculate the number of molecules, we need to consider that there are two Cl (chlorine) atoms in each molecule of MgCl2. First, we calculate the number of moles of MgCl2:
Number of moles = 5.0 moles
Then, we convert it to molecules by multiplying by Avogadro's number:
Number of molecules = 5.0 moles x 6.022 x 10^23 molecules/mole
Number of molecules = 3.011 x 10^24 molecules
d) C2H3NO (acetaldehyde):
To calculate the number of molecules, we follow the same approach as before:
Number of moles = 5.0 moles
Number of molecules = 5.0 moles x 6.022 x 10^23 molecules/mole
Number of molecules = 3.011 x 10^24 molecules
Therefore, the answers are:
a) 3.011 x 10^24 atoms of O
b) 3.011 x 10^24 atoms of N
c) 3.011 x 10^24 molecules of MgCl2
d) 3.011 x 10^24 molecules of C2H3NO
each mole has 6.023*10^23 molecules
each formula show you how many atoms are in the molecule.
So just multiply.