Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

102.0 g/mol.

Explanation:

Aluminum oxide  or Al2O3 is a chemical compound composed of 3 Oxygen and 2 aluminum atoms. Naturally, it is present in the form of mineral corundum in crystalline polymorphic forms. It holds significant importance in the preparation of Aluminium metal that is used as a refractory material.

To calculate the molar mass of Aluminum oxide, we will add the molar mass of 2 Al and 3 O atoms.

                         Since molar mass of Al is: 26.98 g

                               Molar mass of O is: 16.00 g

                                   Molar mass of Al2O3

                                  =   (26.98)2 +  (16.00) 3

                                     =    53.96 +   48

                                       = 101.96 g/mol

Since it is mentioned in question to round off the answer upto 4 significant figures, it will make the 102.0 g/mol.

Hope it help!

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).