1.)Calculate the number of moles in
3.50 x 10^21 atoms of silver. Show all work.
2.) Calculate the number of atoms in 2.58 mol antimony. Show all work
3.) Determine the mass of 1.45 mol FePO4. Show all work.
4.) Calculate the number of mol in 6.75 g of NaCl. Show all work.
5.) What is the volume, in liters, of 2.54 mol methane (CH4) gas? Show all work.
6.) What is the empirical formula of a compound that is 36.2% aluminum and 63.8% sulfur. Show all work.
Thanks so much!!! :)
A mol is 6*10^23 of anything, sort of like a dozen is 12 of anything
so
3.50 x 10^21 atoms (1 mol of atoms/6*10^23 atoms)
= (3.5/6) 10^(-2) = .58*10^-2 mol = 5.8 *10^-3 = .0058 moles
Now with that information and knowing that a mole of any chemical weighs its gram molecular mass I think you can do the rest
for example a mol of water, H2O has mass
2 H + O = 2(1) + 16 = 18 grams
so for water
18 grams is 6*10^23 molecules is one mole
4. mols = grams/molar mass
5. At what pressure? If you mean standard pressure of 760 mm Hg then you need to remember that 1 mol of gas occupies 22.4 L at STP
6. Take a 100 g sample which will be
36.2g Al
63.8g S.
Convert these to mols by mols = g/atomic mass.
36.2/27 = about 1.34
63.8/32 = about 2
Find the ratio. The easy way to do that is to divide both numbers by the smaller number. This makes the smaller number of the two exactly 1.0.
Al = 1.24/1.24--This is to get qet 1.00
S = 2/1.34 = 1.49
Obviously, the answer is NOT Al1S1.5 because we want whole numbers. But a 1:1.5 ratio also is 2:3 in whole numbers so the empirical formula is Al2S3.
1) To calculate the number of moles in 3.50 x 10^21 atoms of silver, you need to use Avogadro's number, which states that 1 mole of any substance contains 6.022 x 10^23 particles. The equation used to convert from atoms to moles is:
Number of moles = Number of atoms / Avogadro's number
Plugging in the given values:
Number of moles = 3.50 x 10^21 / 6.022 x 10^23
Simplifying:
Number of moles ≈ 0.00581 mol
Thus, there are approximately 0.00581 moles in 3.50 x 10^21 atoms of silver.
2) To calculate the number of atoms in 2.58 moles of antimony, you can use Avogadro's number as well. The equation to convert from moles to atoms is:
Number of atoms = Number of moles x Avogadro's number
Plugging in the given values:
Number of atoms = 2.58 mol x 6.022 x 10^23
Calculating:
Number of atoms ≈ 1.553 x 10^24 atoms
Thus, there are approximately 1.553 x 10^24 atoms in 2.58 moles of antimony.
3) To determine the mass of 1.45 moles of FePO4, you need to use the molar mass of FePO4. The molar mass is the sum of the atomic masses of all the elements in the compound. The equation to calculate the mass is:
Mass = Number of moles x Molar mass
The molar mass of FePO4 can be found by adding up the atomic masses of iron (Fe), phosphorus (P), and four oxygen (O) atoms. Look up the atomic masses and compute the molar mass:
Mass = 1.45 mol x (55.845 g/mol + 30.974 g/mol + 4 * 15.999 g/mol)
Calculating:
Mass ≈ 147.024 g
Thus, the mass of 1.45 moles of FePO4 is approximately 147.024 grams.
4) To calculate the number of moles in 6.75 grams of NaCl, you need to use the molar mass of NaCl. The molar mass is the sum of the atomic masses of sodium (Na) and chlorine (Cl). The equation to convert from grams to moles is:
Number of moles = Mass / Molar mass
The molar mass of NaCl can be found by adding up the atomic masses of sodium and chlorine. Look up the atomic masses and compute the molar mass:
Molar mass of NaCl = 22.990 g/mol + 35.453 g/mol = 58.443 g/mol
Now, calculate the number of moles:
Number of moles = 6.75 g / 58.443 g/mol
Calculating:
Number of moles ≈ 0.1156 mol
Thus, there are approximately 0.1156 moles in 6.75 grams of NaCl.
5) To determine the volume of 2.54 moles of methane (CH4) gas, you can use the ideal gas law. The ideal gas law equation is:
PV = nRT
Where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/mol·K), and T is the temperature in Kelvin.
Rearranging the formula to solve for volume:
V = nRT / P
Given that the temperature and pressure are not provided, we cannot calculate the exact volume. However, we can provide an equation for the volume:
V = 2.54 mol x 0.0821 L·atm/mol·K x T / P
The value of T and P would need to be provided to get the actual volume in liters.
6) To find the empirical formula of a compound, you need to determine the relative number of atoms of each element in the compound. The percentages of aluminum and sulfur in the compound can be used to determine the empirical formula.
First, assume that you have a 100g sample of the compound. Then, convert the given percentages to grams:
Aluminum: 36.2g (36.2% of 100g)
Sulfur: 63.8g (63.8% of 100g)
Next, convert the grams to moles using the molar masses of aluminum (Al = 26.98 g/mol) and sulfur (S = 32.07 g/mol):
Aluminum moles = 36.2g / 26.98 g/mol
Sulfur moles = 63.8g / 32.07 g/mol
Finally, find the simplest ratio of the moles by dividing each value by the smaller number of moles:
Aluminum moles / Smallest Moles = Sulfur moles / Smallest Moles
Simplifying:
(36.2g / 26.98 g/mol) / (36.2g / 26.98 g/mol) = (63.8g / 32.07 g/mol) / (36.2g / 26.98 g/mol)
This gives a ratio of:
1:3.195
Now, round the ratio to the nearest whole number:
1:3
Therefore, the empirical formula of the compound is AlS3.