1) to the nearest gram, what is the molar mass of Al2O3?
2)Br+H3O->HBr+H2O
when this reaction is reversed
what substance acts as an acid? what substance acts as a base ?
Tell me what your problem is with these questions. #1 is simply adding the atomic masses from the periodic table. #2 is knowing the Bronsted-Lowry theory of acids/bases. By the way, you omitted the + sign from the hydronium ion, H3O^+.
1) To find the molar mass of Al2O3, we need to look up the atomic masses of aluminum (Al) and oxygen (O) from the periodic table.
The atomic mass of aluminum (Al) is approximately 26.98 g/mol, and the atomic mass of oxygen (O) is approximately 16.00 g/mol.
Since there are two aluminum (Al) atoms and three oxygen (O) atoms in one molecule of Al2O3, we can calculate the molar mass as follows:
Molar mass of Al2O3 = (2 × atomic mass of Al) + (3 × atomic mass of O)
= (2 × 26.98 g/mol) + (3 × 16.00 g/mol)
= 53.96 g/mol + 48.00 g/mol
= 101.96 g/mol
Therefore, the molar mass of Al2O3 is approximately 101.96 grams per mole.
2) In the reaction Br + H3O -> HBr + H2O, when the reaction is reversed, the HBr molecule acts as an acid, and the H2O molecule acts as a base.
In the forward reaction, H3O+ (hydronium ion) acts as an acid by donating a proton (H+) to Br- (bromide ion), forming HBr. The H2O acts as a base by accepting the proton (H+) from H3O+, forming H2O.
When the reaction is reversed, HBr (hydrogen bromide) acts as an acid by donating a proton (H+) to H2O, forming H3O+. The H2O molecule acts as a base by accepting the proton (H+) from HBr, forming Br- (bromide ion).
So, in the reversed reaction, HBr acts as an acid and H2O acts as a base.