luminum oxide is an important starting material for making cryolite, Na3AlF6 (a compound used to give fireworks their yellow colour). First the aluminum oxide is synthesized from aluminum and then reacted with sodium hydroxide and hydrogen fluoride gas. If 2.6 Mg of aluminum is reacted and all other reactants are in excess, calculate the mass of cryolite formed.

4 Al(s) + 3 O2(g)  2 Al2O3(s)
Al2O3(s) + 6 NaOH(aq) + 12 HF(g)  2 Na3AlF6(s) + 9 H2O(l)

Do you intend 2.6 Mg to mean 2.6 mg (meaning milligrams)?

mols Mg = grams/molar mass
Using the coefficients in the balanced equation, convert mols Al to mols Na3AlF6.
Then mass cryolite = mols x molar mass = ?

Here is how you do the mols conversion.
?mols Al x (2 mols Al2O3/4 mols Al) x (1 mol Na3AlF6/1 mol Al2O3) = ? mols Na3AlF6.

To calculate the mass of cryolite formed, we need to determine the limiting reactant between aluminum and oxygen, and then the limiting reactant between aluminum oxide, sodium hydroxide, and hydrogen fluoride gas.

Step 1: Calculate the molar mass of aluminum (Al)
The molar mass of aluminum is 26.98 g/mol.

Step 2: Calculate the number of moles of aluminum (Al)
We are given that 2.6 Mg of aluminum is reacted. To convert this mass to moles, we need to divide by the molar mass of aluminum.
2.6 Mg = 2.6 x 1000 g = 2600 g
Number of moles of aluminum = mass of aluminum / molar mass of aluminum
Number of moles of aluminum = 2600 g / 26.98 g/mol ≈ 96.33 mol

Step 3: Calculate the number of moles of oxygen (O2)
From the balanced chemical equation, we can see that the stoichiometric ratio between aluminum and oxygen is 4:3. Therefore, the number of moles of oxygen can be calculated as:
Number of moles of oxygen = (4/3) x Number of moles of aluminum
Number of moles of oxygen = (4/3) x 96.33 mol ≈ 128.44 mol

Step 4: Determine the limiting reactant between aluminum and oxygen
Since the ratio of aluminum to oxygen is 4:3, and we have 96.33 mol of aluminum and 128.44 mol of oxygen, we can see that aluminum is the limiting reactant. This means that all the aluminum will react, and there will be an excess of oxygen.

Step 5: Calculate the number of moles of aluminum oxide (Al2O3)
From the balanced chemical equation, we can see that the stoichiometric ratio between aluminum and aluminum oxide is 4:2. Therefore, the number of moles of aluminum oxide can be calculated as:
Number of moles of aluminum oxide = (2/4) x Number of moles of aluminum
Number of moles of aluminum oxide = (2/4) x 96.33 mol ≈ 48.16 mol

Step 6: Calculate the mass of aluminum oxide (Al2O3)
The molar mass of aluminum oxide is 101.96 g/mol. We can calculate the mass of aluminum oxide as:
Mass of aluminum oxide = Number of moles of aluminum oxide x Molar mass of aluminum oxide
Mass of aluminum oxide = 48.16 mol x 101.96 g/mol ≈ 4913.78 g ≈ 4.91378 kg

Step 7: Calculate the mass of cryolite (Na3AlF6)
From the balanced chemical equation, we can see that the stoichiometric ratio between aluminum oxide and cryolite is 1:2. Therefore, the mass of cryolite can be calculated as:
Mass of cryolite = 2 x Mass of aluminum oxide
Mass of cryolite = 2 x 4.91378 kg ≈ 9.82756 kg

Therefore, the mass of cryolite formed is approximately 9.82756 kg.