Which has maximum number of atoms?

Mixture X = 0.02 mol of [Co(NH₃)₅SO₄]Br and 0.02 mol of [Co(NH₃)₅Br]SO₄ was prepared in 2 litre of solution.
1 litre of mixture X + excess AgNO₃ $$ \to $$ Y.
1 litre of mixture X + excess BaCl₂ $$ \to $$ Z
No. of moles of Y and Z are

How many moles of electron weigh one kilogram?

The reaction, $$3Cl{O^ - }(aq)$$$$ \to ClO_3^ - (aq) + 2C{l^ - }(aq)$$ is an example of :