First reaction principle of industrial tin smelting

Conservation of elements: aM=C2O2, indicating that a=2 and m = co

2SnO2+3C === 2Sn+2CO+2co (gas) +CO2 (gas)

2SnO2 → 8e- and valence reduction → 2Sn were obtained.

2C → 4e- Loss, valence increase → 2CO.

C → 4e- loss, valence increase → CO2

A, conservation of elements: aM=C2O2, a=2, M=CO, right.

B, the valence of SnO2 is reduced, it is an oxidant, and the reduction reaction occurs.

C, the valence increases after the reaction. (c) There are two substances (carbon monoxide and carbon dioxide).

D, every time 1molCO2 is generated, 8mol of electrons are transferred, right.

To sum up, ABCD is correct (and analyzed)