Respuesta :
1. How many molecules are in 2.0 moles of hydrogen gas (H₂)?
There are 6.022 * 10^23 particles in one mol of particles. There are 6.022 * 10^23 molecules of a compound in one mol of molecules of that compound.
We can compare a mol with a dozen. When we want a dozen eggs, we are asking for 12 eggs. When we say a mol of eggs, we want 6.022 * 10^23 eggs.
1 mol of molecules = 6.022 * 10^23 molecules
We will use that relationship to find the answer to our problem.
number of molecules of H₂= 2.0 moles of H₂ * 6.022 * 10^23 molecules of H₂/(1 mol of H₂)
number of molecules of H₂ = 1.2 * 10^24 molecules
Answer: there are 1.2 * 10^24 molecules of hydrogen gas in 2.0 moles of it.
2. How many moles is 2.0 x 10^25 particles of silver nitrate (AgNO₃)?
1 mol of molecules = 6.022 * 10^23 molecules
number of moles of AgNO₃ = 2.0 x 10^25 molecules/(6.022 * 10^23 molecules/mol)
number of moles of AgNO₃ = 33 moles
Answer: there are 33 moles in 2.0 x 10^25 particles of silver nitrate.
3. How many atoms of oxygen are in 2.4 x 10^23 molecules of copper(II) sulfate (CuSO₄)?
The formula of copper (II) sulfate is CuSO₄. So, one molecule of CuSO₄ has 4 atoms of O.
1 molecule of CuSO₄ = 4 atoms of O
We will that relationship to find the answer to our problem.
number of atoms of O = 2.4 * 10^23 molecules of CuSO₄ * 4 atoms of O/(1 molecule of CuSO₄)
number of atoms of O = 9.6 * 10^23 atoms
Answer: there are 9.6 * 10^23 atoms in 2.4 * 10^23 molecules of CuSO₄.
