The decomposition of 19.6 g of ME (OH) 2 gave 16 g of a bivalent metal oxide. Determine the metal.

Given
m (Me (OH) 2) = 19.6g
m (MeO) = 16g
Decision
1.Write the reaction equation:
Me (OH) 2 = MeO + H2O (when heated)
2. find the mass of water
m (H20) = 19.6-16 = 3.6 g
The sum of the masses of the products before the reaction is equal to the sum of the masses of the products after the reaction
3. find the amount of substance by the formula n = m / M, where n is the amount of substance, m is the mass of the substance, M is the molar mass of the substance
n (H20) = 3.6 / 18 = 0.2 mol
4. find the molar mass of the oxide by the formula M = m / n
M (MeO) = 16: 0.2 = 80 g / mol
5. find the atomic mass of the metal
Ar (Me) = 80-16 = 64 g / mol – Cu, copper
Answer: copper