化学计算是从量的方面来反映物质的组成、结构、性质及变化规律的,具有信息量大、情境新颖、综合性强等特点.它不仅能考查同学们的理解能力和自学能力,还能考查同学们应用各方面知识进行判断、推理和分析、综合的能力以及抽象思维能力.因此,这类试题区分度较大,具有较强的选拔 Chemical calculations reflect the composition, structure, properties, and laws of change in terms of quantity. They have the characteristics of large amounts of information, novel situations, and comprehensive characteristics. They can not only test the students’ understanding ability and self-learning ability, but also Examine the students’ application of various aspects of knowledge for judgment, reasoning and analysis, comprehensive ability and abstract thinking ability. Therefore, such questions are more discriminative and have stronger selection.