硝酸是一种氧化性酸,其氧化能力与自身浓度有密切的关系,与同一金属反应时,酸愈稀,则被还原的程度愈大,一般地说,浓硝酸总是被还原为 NO_2,稀硝酸通常被还原为 NO 和氧化态为+2价以下的产物。Cu+4HNO_3(浓)=Cu(NO_3)2+2NO_2↑+2H_2O3Cu+8HNO_3(稀)=3Cu(NO_3)_2+2NO↑+4H_2O然而,在中学教学中,学生对“浓硝酸被还原的程度小,而稀硝酸被还原的程度大”往往很难理解,并且容易 Nitric acid is an oxidizing acid, and its oxidizing ability is closely related to its own concentration. When reacting with the same metal, the acid becomes thinner and the degree of reduction is greater. In general, concentrated nitric acid is always reduced to NO2. Dilute nitric acid is usually reduced to NO and products with an oxidation level of +2 or lower. Cu+4HNO_3(concentrated)=Cu(NO_3)2+2NO_2↑+2H_2O3Cu+8HNO_3(rare)=3Cu(NO_3)_2+2NO↑+4H_2O However, in the teaching of middle school, the students’ “degree of reduction of concentrated nitric acid is small. , and the dilute nitric acid is reduced to a large degree" is often difficult to understand and easy to