Find the mass in grams.
a. 4.30 x 10^16 atoms He, 4.00 g/mol
b. 5.710 x 10^23 molecules CH4, 16.05 g/mol
c. 3.012 x 10^24 ions Ca^2+, 40.08 g/mol
a. divide the atoms by avogradros number to the moles, then multiply by 4g/mol
so a= 1.075*10^16
To find the mass in grams for each scenario, you need to use the Avogadro's number and the molar mass of the given substance. The steps involved are as follows:
a. 4.30 x 10^16 atoms He, 4.00 g/mol:
1. Start with the given number of atoms (4.30 x 10^16 atoms).
2. Determine the molar mass of helium by referencing the periodic table, which is 4.00 g/mol.
3. Use Avogadro's number (6.022 x 10^23) to convert the number of atoms to moles. Divide the given number of atoms by Avogadro's number.
(4.30 x 10^16 atoms / 6.022 x 10^23 atoms/mol = 7.14 x 10^-8 mol)
4. Finally, multiply the number of moles by the molar mass to find the mass in grams.
(7.14 x 10^-8 mol x 4.00 g/mol = 2.86 x 10^-7 g)
Therefore, the mass of 4.30 x 10^16 atoms of helium is approximately 2.86 x 10^-7 grams.
b. 5.710 x 10^23 molecules CH4, 16.05 g/mol:
1. Begin with the given number of molecules (5.710 x 10^23 molecules).
2. Determine the molar mass of methane (CH4) by summing the molar masses of its constituent elements: carbon (12.01 g/mol) and hydrogen (1.01 g/mol).
(1 carbon x 12.01 g/mol) + (4 hydrogen x 1.01 g/mol) = 16.05 g/mol
3. Use Avogadro's number to convert the number of molecules to moles. Divide the given number of molecules by Avogadro's number.
(5.710 x 10^23 molecules / 6.022 x 10^23 molecules/mol = 0.949 mol)
4. Multiply the number of moles by the molar mass to find the mass in grams.
(0.949 mol x 16.05 g/mol = 15.23 g)
Therefore, the mass of 5.710 x 10^23 molecules of methane is approximately 15.23 grams.
c. 3.012 x 10^24 ions Ca^2+, 40.08 g/mol:
1. Begin with the given number of ions (3.012 x 10^24 ions).
2. Determine the molar mass of calcium ions (Ca^2+). To do this, find the molar mass of calcium (40.08 g/mol) on the periodic table.
3. Use Avogadro's number to convert the number of ions to moles. Divide the given number of ions by Avogadro's number.
(3.012 x 10^24 ions / 6.022 x 10^23 ions/mol = 5.00 mol)
4. Multiply the number of moles by the molar mass to find the mass in grams.
(5.00 mol x 40.08 g/mol = 200.40 g)
Therefore, the mass of 3.012 x 10^24 calcium ions is approximately 200.40 grams.
You must learn to do these yourself. They are worked the same way I showed you earlier in the evening except there are two factors. One to convert molecules or atoms to moles and the second to change from moles to grams.
#molecules x (1 mole/6.02 x 10^23 molecules) x (zz grams/mole) = ?? grams.