Question

1. How many moles are in 4.5 x 1022 atoms of Cu?

2. How many moles are in 8.5 x 1024 molecules of Nz?


3. How many molecules are in 0.025 moles of CH4?


4. How many atoms are contained in 1.26 moles of Pb?


5. How many molecules are in 0.56 moles of CO2?

Answer 1

To calculate the number of moles, you divide the number of atoms or molecules by Avogadro's number. For example, there are 0.0748 moles of Cu in 4.5 x 10^22 atoms. Likewise, there are 14.1 moles of Nz in 8.5 x 10^24 molecules. Another example is 0.56 moles of CO2 which corresponds to 3.37 x 10^23 molecules.

Step-by-step explanation:

1. To calculate the number of moles from the given number of atoms, you can use Avogadro's number, which states that there are 6.022 x 1023 atoms in 1 mole of any substance. Therefore, to calculate the number of moles in 4.5 x 1022 atoms of Cu, you divide the number of atoms by Avogadro's number:

4.5 x 1022 atoms Cu / 6.022 x 1023 atoms/mol = 0.0748 moles Cu

2. For molecules, you can use the same method. Avogadro's number tells you the number of molecules in 1 mole. To calculate the number of moles in 8.5 x 1024 molecules of Nz:

8.5 x 1024 molecules Nz / 6.022 x 1023 molecules/mol = 14.1 moles Nz

3. To calculate the number of molecules in 0.025 moles of CH4, you can use Avogadro's number:

0.025 moles CH4 x 6.022 x 1023 molecules/mol = 1.51 x 1022 molecules CH4

4. For the number of atoms in 1.26 moles of Pb, you can use Avogadro's number:

1.26 moles Pb x 6.022 x 1023 atoms/mol = 7.58 x 1023 atoms Pb

5. To calculate the number of molecules in 0.56 moles of CO2, you can use Avogadro's number:

0.56 moles CO2 x 6.022 x 1023 molecules/mol = 3.37 x 1023 molecules CO2

Answer 2

Know this

(i) 1mole of a substance contains 6.022 x 10^23atoms

(ii) 1mole of a substance contains 6.022x10^23molecules

Now

1.) 4.5x10²²atoms of Cu x 1mole of Cu/6.022x10²³atoms of Cu

=0.075moles of Cu.

2.) 8.5x10²⁴molecules of N2 x 1mole of N2/6.022x10²³molecules

=14.11moles of N2

3.) 0.025moles of CH4 x 6.022x10²³molecules/1mole of CH4

=1.51x10²²molecules of CH4

4.)1.26moles of Pb x 6.022x10²³atoms/1mole of Pb

=7.59x10²³atoms of Pb

5.) 0.56moles of CO2 x 6.022x10²³molecules/1mole

=3.37x10²³molecules.

That's pretty Much Everything