contestada

Which of the following is an oxidation-reduction reaction?
• SO2(g) + H2O(1) H2SO3(aq)
• CaCO3(s) , Cao(s) + CO2(g)
Ca(OH)2(s) + H2CO3(1) CaCO3(aq) + 2H2O(1)
• CsH1206(s) + 602(9) _ , 6C02(g) + 6H20 (7