Question

Mr(Fe2O3) Mr(O2) Mr(HF)

Answer 1

Mr(Fe2O3) = 2Ar(Fe)+3Ar(O) = 2*56+3*16=112+48 =1 60
Mr(O2) = 16.
Mr(HF) = H+F;1+19 = 20

Answer 2

Mr(Fe2O3) refers to the molar mass of Fe2O3, Mr(O2) refers to the molar mass of O2, and Mr(HF) refers to the molar mass of HF. To calculate the molar mass of a compound, we need to sum up the atomic masses of all the atoms in the compound.

The molar mass of Fe2O3 can be calculated as follows: - The atomic mass of Fe is 55.845 g/mol. - The atomic mass of O is 15.999 g/mol. - Since there are two Fe atoms and three O atoms in Fe2O3, we multiply the atomic masses by their respective coefficients and sum them up: Mr(Fe2O3) = (2 * 55.845 g/mol) + (3 * 15.999 g/mol) = 159.69 g/mol.

The molar mass of O2 can be calculated as follows: - The atomic mass of O is 15.999 g/mol. - Since there are two O atoms in O2, we multiply the atomic mass by the coefficient: Mr(O2) = 2 * 15.999 g/mol = 31.998 g/mol.

The molar mass of HF can be calculated as follows: - The atomic mass of H is 1.00784 g/mol. - The atomic mass of F is 18.9984032 g/mol. - Since there is one H atom and one F atom in HF, we sum up the atomic masses: Mr(HF) = 1.00784 g/mol + 18.9984032 g/mol = 20.0062432 g/mol.

Therefore, the molar masses are: - Mr(Fe2O3) = 159.69 g/mol - Mr(O2) = 31.998 g/mol - Mr(HF) = 20.0062432 g/mol

Please note that the molar masses provided are approximate values and may vary slightly depending on the atomic masses used.