Chemistry Question

M2O is an oxide of metal M. Upon heating, M2Odecomposes to give M and oxygen only.
a) Suggest a method for testing oxygen, and state the expected observation.
b) In an experiment, 3.48 g of M2O completely decomposes to give 3.24 g of M. Calculate the relative atomic mass of M.
c) Explain whether M can react with dilute hydrochloric acid.


a)
Test it with a glowing splint. Oxygen can relight the glowing splint.

b)
Let y be the relative atomic mass of M.
Mole ratio M : O in M2O is
3.24/y : (3.48 - 3.24)/16 = 2 : 1
3.24/y = (0.24/16) x 2
3.24/y = 0.03
y = 3.24/0.03
The relative atomic mass of M, y = 108

c)
No.
M2O decomposes on heating. It can be deducted that M is very unreactive. Since M is less reactive than hydrogen, M cannot displace hydrogen from hydrochloric acid.