Xiao Huang Wei Zi

(2)Zn+2HCl=ZnCl2+H2 (upward arrow)

(3) Increase the surface area of the alloy and speed up the reaction.

(4) After installing the instrument, hold the test tube by hand and observe whether the liquid level in the C tube changes. If the liquid level does not change, it means that the device is leaking, and if the liquid level drops, it means that the device is airtight.

(5) Make the liquid level in the D tube consistent with that in the C tube to ensure the pressure inside and outside the device is consistent.

(6) Lack of the step of measuring the initial weight of alloy powder.

(7) The experiment should be repeated. At this point, the gas generated inside produced a certain liquid level drop in the C tube. It shows that the gas in the closed reactor is increasing. If the closed reactor is opened at this time, measuring the generated gas will get wrong volume data.