(Junior high school chemistry, emergency) Generally, substances such as Ca(HCO3)2 and Mg(HCO3)2 are dissolved in natural water, and these dissolved substances will change under heating conditions.

Dissolve 1 in water, filter the filtrate, introduce CO2, and there is no obvious phenomenon, or add phenolphthalein solution to the filtrate, and the solution will not turn red.

CO2 in device 2 A cannot completely enter device B, and there will be impurities such as water vapor. In addition, CO2 in the air will enter the solution through the catheter on the right side of device B, which will affect the detection results.

Because calcium carbonate-carbon dioxide

100g 44g

x 2.2g x=5

Because the scale contains Mg(OH)2 and CaCO3, there must be substances that produce CO2, and their average value is more than CaCO3, which can satisfy the question. Otherwise, the mixture of 5gMg(OH)2 and CaCO3 must produce less than 5g, so it is presumed to be MgC03.

Magnesium carbonate-carbon dioxide

84g 44g

5g 2.62g & gt2.2g

Therefore, the main component is mgc03mg (oh) 2co3.

This is just my answer, for reference only.