Question

32 g of a metal, M, reacts with 8 g of oxygen to form an oxide. The formula of the oxide is MO. What is the atomic mass of M in g mol-?
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Answer 1

Answer: M= 128 g/mol (Te is quite close)

Explanation: number of Oxygen moles is n = 8 g / 32 g/mol = 0,25 mol.

Because formula of oxide is MO, thus amount of metal is also 0,25 mol.

Because n = m/M , Molar mass of the metal M = m/n = 32 g /0.25 mol = 128 g/ mol