how to set up or approach these
1. Calculate the mass in grams of iodine (I2) that will react completely with 48.9 g of aluminum (Al) to form aluminum iodide (AlI3).
Do I need to find the mass as a whole for the entire compound, then convert?
2. The formula for rust can be represented by Fe2O3. How many moles of Fe are present in 24.4 g of the compound
And I don't know how to get started on this one.
you have to go
mol=g/mm
mol=grams/molecular mass
to find how many moles are in Fe2O3
For the AlI3 question.
1.Writ the equation and balance it.
2.Convert 48.9 g Al to moles; moles = grams/atomic mass.
3.Using the coefficients in the balanced equation, convert moles Al to moles AlI3.
4.Convert moles AlI3 to grams. grams = moles x molar mass.
Post your work if you get stuck.
For the second part.
moles = grams/molar mass.
To approach the first question, you need to determine the mass of iodine (I2) that will react completely with the given mass of aluminum (Al) to form aluminum iodide (AlI3). Here's how you can do it:
1. Write the balanced chemical equation for the reaction:
2 Al + 3 I2 -> 2 AlI3
2. Determine the molar mass of aluminum:
The molar mass of aluminum (Al) is 26.98 g/mol.
3. Determine the molar mass of iodine:
The molar mass of iodine (I2) can be calculated by adding the atomic masses of two iodine atoms. The atomic mass of iodine is 126.90 g/mol, so the molar mass of I2 is 2 * 126.90 g/mol = 253.8 g/mol.
4. Calculate the number of moles of aluminum (Al):
Using the given mass of aluminum (Al) which is 48.9 g, divide it by the molar mass of aluminum to get the number of moles.
Number of moles = mass / molar mass = 48.9 g / 26.98 g/mol = 1.809 mol (rounded to three decimal places).
5. Determine the mole ratio between aluminum (Al) and iodine (I2) from the balanced chemical equation:
According to the balanced equation, 2 moles of aluminum react with 3 moles of iodine. So, the mole ratio is 2:3.
6. Calculate the number of moles of iodine (I2):
To find the moles of iodine that will react with the given moles of aluminum, use the mole ratio.
Number of moles of iodine = (Number of moles of aluminum) * (Mole ratio)
= 1.809 mol * (3 moles of iodine / 2 moles of aluminum)
= 2.7145 mol (rounded to four decimal places)
7. Calculate the mass of iodine:
To convert the moles of iodine to its mass, multiply the number of moles by the molar mass of iodine (I2).
Mass of iodine = (Number of moles of iodine) * (Molar mass of iodine)
= 2.7145 mol * 253.8 g/mol
= 689.615 g (rounded to three decimal places)
Therefore, the mass of iodine required to react completely with 48.9 g of aluminum is approximately 689.615 grams.
Now, let's move on to the second question:
To determine the number of moles of Fe in 24.4 g of Fe2O3 (rust compound), you can follow these steps:
1. Determine the molar mass of Fe2O3:
The molar mass of Fe2O3 can be calculated by adding the atomic masses of two iron (Fe) atoms and three oxygen (O) atoms. The atomic mass of iron is 55.85 g/mol, and the atomic mass of oxygen is 16.00 g/mol.
Molar mass of Fe2O3 = (2 * 55.85 g/mol) + (3 * 16.00 g/mol) = 159.70 g/mol.
2. Calculate the number of moles of Fe2O3:
Using the given mass of Fe2O3, which is 24.4 g, divide it by the molar mass of Fe2O3 to determine the number of moles.
Number of moles = mass / molar mass = 24.4 g / 159.70 g/mol = 0.1527 mol (rounded to four decimal places).
3. Determine the mole ratio between Fe and Fe2O3 from the balanced chemical equation:
According to the balanced chemical equation, 2 moles of Fe react with 1 mole of Fe2O3. So, the mole ratio is 2:1.
4. Calculate the number of moles of Fe:
To find the moles of Fe present in the given moles of Fe2O3, use the mole ratio.
Number of moles of Fe = (Number of moles of Fe2O3) * (Mole ratio)
= 0.1527 mol * (2 moles of Fe / 1 mole of Fe2O3)
= 0.3055 mol (rounded to four decimal places).
Therefore, there are approximately 0.3055 moles of Fe present in 24.4 g of Fe2O3.