A toothpaste contains 0.220 % by mass sodium fluoride used to prevent dental caries and 0.32 % by mass triclosan C12H7Cl3O2, an antigingivitis agent. One tube contains 119 g of toothpaste.

How many fluoride ions, F−, are in the tube of toothpaste?
How many grams of sodium ion, Na+, are in 1.70 g of toothpaste?
How many molecules of triclosan are in the tube of toothpaste?

To find the number of fluoride ions (F-) in the tube of toothpaste, we first need to calculate the mass of sodium fluoride (NaF) in the toothpaste.

Step 1: Calculate the mass of sodium fluoride in the toothpaste.
Given that the toothpaste contains 0.220% sodium fluoride and one tube contains 119 g of toothpaste, we can calculate the mass of sodium fluoride as follows:

Mass of sodium fluoride = (0.220/100) * 119 g
= 0.26 g

Step 2: Calculate the number of moles of sodium fluoride.
To do this, we need to know the molar mass of sodium fluoride. The molar mass of sodium (Na) is 22.99 g/mol, and the molar mass of fluorine (F) is 18.998 g/mol.
The molar mass of sodium fluoride (NaF) is:
Molar mass of NaF = 22.99 g/mol + 18.998 g/mol
= 41.988 g/mol

Now we can calculate the number of moles of sodium fluoride:
Number of moles of NaF = Mass of NaF / Molar mass of NaF
= 0.26 g / 41.988 g/mol
≈ 0.00619 mol

Step 3: Calculate the number of fluoride ions.
Since one mole of sodium fluoride contains one mole of fluoride ions, we can say that the number of fluoride ions is equal to the number of moles of sodium fluoride:

Number of fluoride ions = Number of moles of NaF
≈ 0.00619 mol

Therefore, there are approximately 0.00619 moles of fluoride ions in the tube of toothpaste.

To find the grams of sodium ion (Na+) in 1.70 g of toothpaste, we first need to calculate the molar mass of sodium ion.

The molar mass of sodium (Na) is 22.99 g/mol, and since sodium has a +1 charge, the molar mass of sodium ion (Na+) is also 22.99 g/mol.

Now we can calculate the number of moles of sodium ion in 1.70 g of toothpaste:

Number of moles of Na+ = Mass of Na+ / Molar mass of Na+
= 1.70 g / 22.99 g/mol
≈ 0.0739 mol

Therefore, there are approximately 0.0739 moles of sodium ions in 1.70 g of toothpaste.

To find the number of molecules of triclosan (C12H7Cl3O2) in the tube of toothpaste, we first need to calculate the number of moles of triclosan.

Step 1: Calculate the molar mass of triclosan.
The molar mass of carbon (C) is 12.01 g/mol, hydrogen (H) is 1.008 g/mol, chlorine (Cl) is 35.45 g/mol, and oxygen (O) is 16.00 g/mol.
The molar mass of triclosan (C12H7Cl3O2) is:

Molar mass of triclosan = (12.01 g/mol * 12) + (1.008 g/mol * 7) + (35.45 g/mol * 3) + (16.00 g/mol * 2)
≈ 354.452 g/mol

Step 2: Calculate the number of moles of triclosan.
Given that the toothpaste contains 0.32% triclosan and one tube contains 119 g of toothpaste, we can calculate the mass of triclosan as follows:

Mass of triclosan = (0.32/100) * 119 g
= 0.381 g

Now we can calculate the number of moles of triclosan:
Number of moles of triclosan = Mass of triclosan / Molar mass of triclosan
= 0.381 g / 354.452 g/mol
≈ 0.00108 mol

Step 3: Calculate the number of molecules of triclosan.
Since one mole of triclosan contains Avogadro's number of molecules (6.022 x 10^23), we can say that the number of molecules of triclosan is equal to the number of moles of triclosan multiplied by Avogadro's number:

Number of molecules of triclosan = Number of moles of triclosan * Avogadro's number
≈ 0.00108 mol * 6.022 x 10^23 molecules/mol

Therefore, there are approximately 6.502 x 10^20 molecules of triclosan in the tube of toothpaste.