Formic acid to remove water, you can add anhydrous copper sulfate, anhydrous magnesium sulfate to remove water, these are chemical methods, in addition to specific instructions

(1) Add concentrated sulfuric acid liquid to the formic acid, which should be added through the separation funnel. Therefore, the ② device should be selected; Sodium hydroxide solution and calcium hydroxide solution can absorb a small amount of formic acid gas mixed in CO, but the absorption capacity of sodium hydroxide solution is stronger than that of calcium hydroxide solution. Therefore, the device ③ should be selected;

(2) The generated carbon monoxide gas is discharged from B, from D into the sodium hydroxide solution to remove formic acid gas, and from C; And then it goes in from G, under heated conditions. Carbon monoxide reduces copper oxide, the gas is discharged from H, and then enters the calcium hydroxide solution from F to check the formation of carbon dioxide. Therefore, the interface connection sequence of each instrument is: B D C G H F.

(3) Under the condition of heating, copper oxide is reduced to copper, so from the beginning of heating to the end of the experiment, the color of copper oxide powder changes to: black becomes red, and the reaction equation is: CuO+CO

△ Cu+CO2.

(4) According to the meaning of the question, in the reaction of producing CO, concentrated sulfuric acid dehydrates formic acid to produce carbon monoxide, which plays the role of dehydration.

The answer is:

(1) ②, ③;

(2) B D C G H F;

(3) Black to red, CuO+CO △Cu+CO2;

(4) Dehydration.

The main way to discharge the water in formic acid is these, you can carry out specific operations according to the instructions, more information about formic acid and other related products, will continue to be sorted out for you, please pay attention.