(2006?Changzhou second model) The laboratory uses the device shown in the figure to make hydrogen gas, (1) before the experiment, how to check the air tightness of the generating device shown in the figure? ______
(1) check the tightness of the device, you can clamp the spring clip on the rubber tube, add water from the long-necked funnel to submerge the end of the funnel neck, continue to add water to form a liquid column, after a while if the liquid level does not fall, it is a good airtight, so fill in: the spring clip on the rubber tube, from the long-necked funnel to join the water to submerge the end of the funnel neck, and continue to add water to form a liquid column, after a while if the liquid level does not drop, then the airtight is good!
(2) reaction acid is not enough to submerge the zinc particles, and temporarily can not find the acid, to make the reaction start, you need to increase the amount of liquid, you can add water, fill in: test tube with some water;
(3) the device is a solid-liquid ambient type of generator, you can also use the device to use limestone and dilute hydrochloric acid to produce carbon dioxide, fill in: CaCO3+2HCl═ CaCl2+H2O+CO2↑.