Concept:An acid anhydride is a non-metal oxide that reacts with water to form an acid. The strength of the acid produced depends on how fully it ionises in water.
Explanation:Carbon(IV) oxide,
CO2, reacts with water to form trioxocarbonate(IV) acid, commonly called carbonic acid.
The equation is:
CO2(g)+H2O(l)→H2CO3(aq)H2CO3 ionises only partially in water, so it is a weak acid.
In contrast,
SO3 gives tetraoxosulphate(VI) acid,
H2SO4, which is a strong acid.
Nitrogen(IV) oxide,
NO2, also produces strongly acidic products in water.
Therefore, the acid anhydride that produces a weak acid in water is
CO2.
Answer:D.
CO2