The method of the chemical experiment operation test for the senior high school entrance examination in our city is to determine the test questions by the candidates. After the lottery, Xiaoli prepare

The method of the chemical experiment operation test for the senior high school entrance examination in our city is to determine the test questions by the candidates. After the lottery, Xiaoli prepared the following instruments and medicines under the guidance of the invigilator. (1) A balance with medicine and indicating that a certain amount of solid medicine needs to be weighed, a measuring cylinder and a beaker, and a rubber-tipped dropper indicating that water needs to be taken, so the name is to prepare a solution with a certain solute mass fraction;

(2) The instruments needed to prepare the solution are: tray balance, rubber-tipped dropper, beaker, measuring cylinder and glass rod, so there are few glass rods;

(3) The bottle stopper should be inverted on the desktop, otherwise the medicine on the bottle stopper will corrode the desktop and pollute the reagent; Weighing drugs should be divided into left-handed and right-handed, otherwise the weighing quality is small;

(4) The original plan cannot be calculated according to the wrong operation. The weight plus running code is 18g, and the water is 82g, so the mass fraction is:18g+82g×100% =18%.

So the answer is: (1) prepare a solution with a certain solute mass fraction; (2) glass rod; (3) The bottle stopper of the reagent is not inverted; When weighing, the weight and salt are inverted; (4) 18%.