Answer:
a) Iron(ll) acetate tetrahydrate: 245,68 g/mol
b) Sulfur tetrachloride: 173,87 g/mol
c) Potassium ermanganate 158,034 g/mol
Explanation:
To solve this kind of exercises you must look for the number of atoms in each molecule first, then look on the periodic table the atom weight and the multiply the atom weight times the quantity of each atom. For instance:
The molecule of Iron(II) acetate itetrahydrate is (CH3COO)2Fe•4H2O, it means that you have:
2 atoms of carbon times the atomic weight of C (12.00g/mol)= 24g
14 atoms of Hidrogen times the atomic weight of H (1,00g/mol)= 14g
6 atoms of Oxigen times the atomic weight of O (16,0g/mol)= 96
2 atoms of Iron times the atomic weight of Fe (55,84g/mol)= 111,68g
At last, you only have to add the results: 24+14+96+11,68= 245,68g/mol. This example was for the first molecule.
See you,
