用逆向思维法解题的步骤一般为：（１）依据题意写出化学方程式，列出已知量、要求的量，对于较复杂的题要画出框图；（２）找出所用物理量之间的关系式；（３）由解题目标推出必要条件，最后确定所缺数据的物理量并确定其单位。现举例说明逆向思维法在解下列缺数据题中的应用 The steps to solve problems with reverse thinking are generally as follows: (1) Write the chemical equations according to the questions, list the known quantities and required quantities, and draw a block diagram for more complicated questions; (2) Find out the physical quantities used The relationship between; (3) from the problem objectives to introduce the necessary conditions, the final determination of the missing physical data and determine the unit. An example is given to illustrate the application of the inverse thinking method in solving the following missing data questions