Sulfuric acid can dissolve aluminum metal according to the following reaction.
2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g) Suppose you wanted to dissolve an aluminum block with a mass of 26.8 g .
1.What minimum amount of H2SO4 in grams would you need?
2.How many grams of H2 gas would be produced by the complete reaction of the aluminum block?
2Al + 3H2SO4→Al2(SO4)3 + 3H2
mols Al = grams/atomic mass Al.
Using the coefficients in the balanced equation, convert mols Al to mols H2SO4. That will be mols Al x 3/2 = mols H2SO4.
Now convert mols H2SO4 to grams. grams = mols x molar mass = ?
2.
mols Al from above.
Convert mols Al to mols H2 gas as above.
Convert mols H2 to grams as above.
1. Well, well, well, looks like we have an aluminum block that's feeling a bit too attached to its mass. To dissolve it, we'll need to break out the big guns: sulfuric acid. According to the reaction equation, we need 3 moles of H2SO4 for every 2 moles of Al. Now, the molar mass of Al is 26.98 g/mol, so the mass of our aluminum block is 26.8 g / 26.98 g/mol = 0.993 moles of Al. Since we need 2 moles of Al for every 3 moles of H2SO4, we can calculate the minimum amount of H2SO4 needed as follows: 0.993 mol Al × (3 mol H2SO4 / 2 mol Al) × (98.08 g/mol H2SO4) = 47.22 g H2SO4. So, you would need a minimum of 47.22 grams of sulfuric acid to dissolve that aluminum block.
2. Ah, the sweet symphony of gas production! According to the reaction, for every 2 moles of Al, we get 3 moles of H2 gas. We already calculated that we have 0.993 moles of Al, so let's see how much H2 gas that gives us: 0.993 mol Al × (3 mol H2 / 2 mol Al) × (2.016 g/mol H2) = 3.02 g H2. Voila! We have a delightful 3.02 grams of H2 gas being produced from the complete reaction of the aluminum block. Now that's some real gas-passing talent right there!
To determine the minimum amount of H2SO4 needed to dissolve the aluminum block and the mass of H2 gas produced, we need to use stoichiometry.
1. Calculating the minimum amount of H2SO4 required:
Based on the balanced equation, the molar ratio of aluminum to H2SO4 is 2:3. We can use this ratio to find the number of moles of H2SO4 needed.
First, convert the mass of the aluminum block to moles of aluminum:
molar mass of aluminum (Al) = 26.98 g/mol
moles of Al = mass of Al / molar mass of Al
moles of Al = 26.8 g / 26.98 g/mol
Since the ratio is 2:3, the moles of H2SO4 needed will be:
moles of H2SO4 = (3/2) * moles of Al
Now, calculate the mass of H2SO4 using the molar mass of H2SO4:
molar mass of H2SO4 = 98.09 g/mol
mass of H2SO4 = moles of H2SO4 * molar mass of H2SO4
2. Calculating the mass of H2 gas produced:
Based on the balanced equation, the molar ratio of H2 to aluminum is 3:2. We can use this ratio to find the number of moles of H2 gas produced.
Using the same number of moles of aluminum as calculated in step 1:
moles of H2 = (3/2) * moles of Al
Finally, calculate the mass of H2 gas using its molar mass:
molar mass of H2 = 2.02 g/mol
mass of H2 = moles of H2 * molar mass of H2
Plug in the values to calculate the answers.
To determine the minimum amount of H2SO4 required to dissolve the aluminum block, you need to use stoichiometry. Here's how you can calculate it:
1. Calculate the molar mass of aluminum (Al):
The molar mass of Al is 26.98 g/mol.
2. Set up a stoichiometric ratio using the balanced equation:
From the balanced equation, the stoichiometric ratio between Al and H2SO4 is 2:3. This means that for every 2 moles of Al, you need 3 moles of H2SO4.
3. Convert the mass of Al to moles:
Divide the mass of Al (26.8 g) by the molar mass of Al (26.98 g/mol) to get the number of moles of Al.
Moles of Al = mass of Al / molar mass of Al
= 26.8 g / 26.98 g/mol
≈ 0.995 moles of Al
4. Use the stoichiometric ratio to calculate the moles of H2SO4:
Since the stoichiometric ratio is 2:3 between Al and H2SO4, the moles of H2SO4 are directly proportional to the moles of Al.
Moles of H2SO4 = (3/2) * moles of Al
= (3/2) * 0.995 moles
≈ 1.493 moles of H2SO4
5. Convert moles of H2SO4 to grams:
Multiply the number of moles of H2SO4 by its molar mass to get the mass of H2SO4 required.
Mass of H2SO4 = moles of H2SO4 * molar mass of H2SO4
To determine the grams of H2 gas produced by the complete reaction of the aluminum block, you can use the stoichiometric ratio from the balanced equation:
1. Calculate the molar mass of H2 (hydrogen gas):
The molar mass of H2 is 2.02 g/mol.
2. Use the stoichiometric ratio between Al and H2 to calculate the moles of H2 produced:
From the balanced equation, the stoichiometric ratio between Al and H2 is 2:3. This means that for every 2 moles of Al, 3 moles of H2 will be produced.
Moles of H2 = (3/2) * moles of Al
3. Calculate the moles of H2 produced by the aluminum block:
Multiply the moles of H2 by the molar mass of H2 to get the mass of H2 produced.
Mass of H2 = moles of H2 * molar mass of H2
By performing these calculations, you can determine the minimum amount of H2SO4 required and the grams of H2 gas produced by the complete reaction of the aluminum block.