Specify the oxides that react with alkalis: A) SO3 B) CО2 B) К2O D) NO2 E) CuО E) ZnCl2

Of the oxides, only acidic and amphoteric oxides react with alkalis. Let’s define the nature of these oxides:
1. SO3 – acidic oxide. 2NaOH + SO3 = Na2SO4 + H2O
2. CO2 is an acidic oxide. 2NaOH + CO2 = Na2CO3 + H2O
3. K2O – basic oxide, does not react with base (alkali)
4. NO2 – acidic oxide. 2NaOH + 2NO2 = NaNO2 + NaNO3 + H2O
5. CuO – basic oxide, does not react with base (alkali)
ZnCl2 – salt, reacting with alkali forms an insoluble base Zn (OH) 2
2NaOH + ZnCl2 = Zn (OH) 2 + 2NaCl