1) how many molecules are present in 1.5 moles of NaCl?

2) how many atoms of chlorine are in 19.0 grams of MgCl2?

To determine the number of molecules in a given amount of a substance, you need to use Avogadro's number, which is approximately 6.022 x 10^23 molecules per mole.

Let's calculate the number of molecules in 1.5 moles of NaCl:

1) Number of molecules in 1.5 moles of NaCl:
- We'll multiply the number of moles by Avogadro's number:
- Number of molecules = 1.5 moles * 6.022 x 10^23 molecules/mole = 9.033 x 10^23 molecules

Therefore, there are approximately 9.033 x 10^23 molecules in 1.5 moles of NaCl.

Now, let's determine the number of atoms of chlorine in 19.0 grams of MgCl2:

2) Number of atoms of chlorine in 19.0 grams of MgCl2:
- First, calculate the number of moles of MgCl2:
- Number of moles = mass (in grams) / molar mass (in grams/mole)
- The molar mass of MgCl2 is:
- Molar mass of Mg = 24.31 g/mol
- Molar mass of Cl = 35.45 g/mol
- Molar mass of MgCl2 = (2 * Cl) + Mg = (2 * 35.45 g/mol) + 24.31 g/mol = 95.21 g/mol
- Number of moles = 19.0 g / 95.21 g/mol ≈ 0.19956 moles

- Next, determine the number of atoms of chlorine:
- Number of atoms = Number of moles * Avogadro's number
- Number of atoms = 0.19956 moles * 6.022 x 10^23 atoms/mole = 1.201 x 10^23 atoms

Therefore, there are approximately 1.201 x 10^23 atoms of chlorine in 19.0 grams of MgCl2.

To answer these questions, we need to use Avogadro's number and the molecular formulas of the compounds involved.

1) To find the number of molecules in 1.5 moles of NaCl, we need to use Avogadro's number, which is approximately 6.022 x 10^23. Avogadro's number represents the number of entities (atoms, molecules, ions, etc.) in one mole of a substance.

Since the molecular formula of NaCl represents one molecule of sodium chloride, one mole of NaCl contains Avogadro's number of molecules. Therefore, we can calculate the number of molecules in 1.5 moles of NaCl by multiplying 1.5 moles by Avogadro's number:

Number of molecules = 1.5 moles x (6.022 x 10^23 molecules/mole)

2) To determine the number of chlorine atoms in 19.0 grams of MgCl2, we first need to calculate the number of moles of MgCl2 present in the given mass. We can do this by dividing the given mass by the molar mass of MgCl2.

The molar mass of MgCl2 can be found by summing the atomic masses of its constituent elements (magnesium and chlorine) from the periodic table. The atomic mass of magnesium (Mg) is approximately 24.31 g/mol, while the atomic mass of chlorine (Cl) is approximately 35.45 g/mol.

Molar mass of MgCl2 = (atomic mass of Mg x 1) + (atomic mass of Cl x 2)

Next, we can calculate the number of moles of MgCl2 using the formula:

Number of moles = given mass / molar mass

Finally, to determine the number of atoms of chlorine present, we can apply the stoichiometric ratio between MgCl2 and chlorine atoms. The molecular formula of MgCl2 indicates that there are two chlorine atoms for every one molecule of MgCl2.

Number of chlorine atoms = number of moles of MgCl2 x (2 moles of Cl / 1 mole of MgCl2)

By following these steps, you can find the answers to the questions.

1 mole of anything contains 6.02E23 molecules.

Convert 19.0 g MgCl2 to mols. mol = grams/molar mass. Then convert that many mols to molecules MgCl2 (use #1 as a template if needed). Then you notice there are 3 atoms for each molecule so 3x molecules gives you atoms.